Aspose.Slides FOSS for Java

Aspose.Slides FOSS for Java is a free, open-source, pure-Java library for creating, reading, and editing PowerPoint .pptx presentations. The Presentation class is the root of the object model — it owns slides, shapes, images, comment authors, and document properties — and every operation runs without Microsoft Office, COM automation, or any proprietary runtime. Unknown XML content encountered while loading a presentation is never silently discarded on save. The sections below walk through its core features, installation, and full API surface.

It builds the Office Open XML package itself, so it needs no PowerPoint installation, no native code, and no runtime dependencies at all — the CycloneDX SBOM the build produces lists zero components.

It is for developers who generate or modify decks on a server or in a build, and who are working inside the file format. It is not a renderer or a converter: there is no PDF, HTML, SVG, or image output, and everything it cannot do is listed under Scope and Limitations.

Navigation

• At a Glance
• Key Capabilities
• Installation
• Dependencies
• Quick Start
• Additional Examples
• API Reference
• Documentation & Resources
• Scope and Limitations
• Development and Testing
• License

At a Glance

flowchart TD
  subgraph StartingPoints["Starting Points"]
    direction TB
    i1["Nothing — authored from scratch"]
    i2["An existing PPTX presentation"]
  end
  PRODUCT["Aspose.Slides FOSS for Java"]
  subgraph Capabilities["Core Capabilities"]
    direction LR
    subgraph capl[" "]
      direction TB
      c1["Presentation and slide creation and editing"]
      c2["Shape creation (AutoShape, Table, Connector, PictureFrame)"]
      c3["Text formatting (TextFrame, Paragraph, Portion)"]
      c4["Fill, line, and 3D shape styling"]
    end
    subgraph capr[" "]
      direction TB
      c5["Visual effects (shadow, glow, blur, reflection)"]
      c6["Document properties (core, app, custom)"]
      c7["Speaker notes and threaded comments"]
      c8["Image embedding"]
    end
  end
  subgraph Outputs["Outputs"]
    direction TB
    o1["A PPTX presentation"]
  end
  StartingPoints --> PRODUCT --> Capabilities --> Outputs

Key Capabilities

Everything below was exercised through the public API and then confirmed by reading the XML inside the file that came out — not by asking the library to read its own file back.

• The Presentation class is the root of the object model, implements AutoCloseable, and is always used inside a try-with-resources block; open an existing .pptx with new Presentation(path) or start empty with new Presentation(), then persist it with save(path, format) or save(stream, format) to any of the three formats save() writes — SaveFormat.PPTX, PPSX, and POTX — see Scope and Limitations for the rest of SaveFormat.
• Add, remove, and clone slides through SlideCollection's addClone(), addEmptySlide(), insertEmptySlide(), and removeAt() methods, iterate getSlides() directly, and control per-slide visibility during a slideshow with ISlide.setHidden()/isHidden() (written as <p:sld show="0">); MasterSlideCollection.addClone() also exists, but see Scope and Limitations for a real defect in what survives it.
• Insert AutoShapes, PictureFrames, Tables, and Connectors via ShapeCollection's addAutoShape(), addPictureFrame(), addTable(), and addConnector() methods, each returning a real IShape-derived object — 190 ShapeType values are supported, writing 187 distinct <a:prstGeom prst="…"> tokens between them (NOT_DEFINED/CUSTOM both write rect, and ROUND_RECTANGLE/ROUND_CORNER_RECTANGLE both write roundRect).
• Format text at the TextFrame, Paragraph, and Portion level — character formatting (bold, italic, underline, strikethrough, size, spacing, caps, latin/east-Asian/complex-script/symbol fonts) via PortionFormat, paragraph formatting (alignment, indent, margins, spacing, symbol/ numbered/picture bullets) via ParagraphFormat, and frame-level formatting (margins, wrap, anchor, autofit, columns) via TextFrameFormat.

Installation

aspose-slides-foss is published on Maven Central as org.aspose:aspose-slides-foss:26.7.0.

Maven:

<dependency>
    <groupId>org.aspose</groupId>
    <artifactId>aspose-slides-foss</artifactId>
    <version>26.7.0</version>
</dependency>

Gradle:

implementation 'org.aspose:aspose-slides-foss:26.7.0'

Before you depend on 26.7.0, read this. It predates a hardening fix: every parser and serializer in the current source is created by a secure XML factory that refuses a <!DOCTYPE> declaration outright and disables external entities, external DTD loading, and XInclude. 26.7.0 does not have that fix, and SECURITY.md lists it as not supported for that reason — before the fix, a .pptx part could declare an external entity that got resolved while loading the file, so opening a presentation from an untrusted source could read a local file or open a network connection. If your program opens .pptx files that come from somewhere you do not control, build from source (below) rather than depending on 26.7.0.

This source tree is 26.8.0, not yet released to Maven Central — the save-format refusal described under Scope and Limitations is also new in 26.8.0, not in 26.7.0. Until 26.8.0 is out, build from source if you need either fix.

The published jar declares Automatic-Module-Name: org.aspose.slides.foss, so it can go on the module path under a stable name.

JDK 21 or later is required, and the library has no runtime dependencies beyond the JDK itself.

Dependencies

Required Package Dependencies

No required third-party package dependencies.

Native and System Requirements

• JDK 21 or later — maven.compiler.release is pinned to 21 in pom.xml, and the build fails on an older JDK with a readable message rather than silently targeting a downlevel bytecode version. This is enforced, not just declared: the sources use List.getFirst(), List.removeLast(), and an unconditional instanceof pattern, none of which compile below 21.
• Tested on Linux, Windows, and macOS, on Java 21 and Java 25, on every push and every pull request.

Development Dependencies

• org.junit.jupiter:junit-jupiter-api 5.11.4
• org.junit.jupiter:junit-jupiter-engine 5.11.4
• org.junit.jupiter:junit-jupiter-params 5.11.4
• org.assertj:assertj-core 3.27.3

Quick Start

Create a presentation, add a rectangle AutoShape, apply a solid fill, and save it as .pptx:

import org.aspose.slides.foss.Presentation;
import org.aspose.slides.foss.ShapeType;
import org.aspose.slides.foss.FillType;
import org.aspose.slides.foss.IAutoShape;
import org.aspose.slides.foss.ISlide;
import org.aspose.slides.foss.drawing.Color;
import org.aspose.slides.foss.export.SaveFormat;

try (Presentation pres = new Presentation()) {
    ISlide slide = pres.getSlides().get(0);
    slide.getShapes().clear();

    IAutoShape shape = slide.getShapes().addAutoShape(ShapeType.RECTANGLE, 50, 50, 200, 100);
    shape.getFillFormat().setFillType(FillType.SOLID);
    shape.getFillFormat().getSolidFillColor().setColor(Color.fromArgb(255, 0, 128, 255));

    pres.save("hello.pptx", SaveFormat.PPTX);
}

Compiled against this tree and run, this leaves a real, working hello.pptx behind that opens directly in PowerPoint. Three things worth knowing before the second program you write:

• save and the Presentation(String) constructor throw IOException. close() does not, so try-with-resources needs nothing extra.
• IShapeCollection.get(int) returns IShape. Cast to IAutoShape, ITable, IConnector, or IPictureFrame to reach the members only those have. ISlideCollection implements Iterable, so a for-each over getSlides() works; IShapeCollection does not, so iterate it with an index or with getShapes().asIEnumerable().
• Coordinates and sizes are points — 1 point = 1/72 inch. Slide and shape indices are zero-based.

Additional Examples

Every example below was compiled against this tree and run. Beyond basic shape creation, the integration test suite exercises connectors, comments, notes, document properties, effects, and images end to end (create, save, reopen, re-verify). The flagship example below wires two shapes together with a connector; more usage examples are collapsed below it.

Connect two shapes with a bent connector, choosing a specific connection site on each end:

import org.aspose.slides.foss.*;
import org.aspose.slides.foss.export.SaveFormat;

try (Presentation pres = new Presentation()) {
    ISlide slide = pres.getSlides().get(0);
    slide.getShapes().clear();

    IAutoShape s1 = slide.getShapes().addAutoShape(ShapeType.RECTANGLE, 50, 50, 100, 60);
    IAutoShape s2 = slide.getShapes().addAutoShape(ShapeType.RECTANGLE, 350, 200, 100, 60);
    IConnector conn = slide.getShapes().addConnector(ShapeType.BENT_CONNECTOR3, 0, 0, 1, 1);

    conn.setStartShapeConnectedTo(s1);
    conn.setStartShapeConnectionSiteIndex(3);
    conn.setEndShapeConnectedTo(s2);
    conn.setEndShapeConnectionSiteIndex(1);

    pres.save("connector.pptx", SaveFormat.PPTX);
}

Add a Threaded Comment to a Slide

import org.aspose.slides.foss.*;
import org.aspose.slides.foss.drawing.PointF;
import org.aspose.slides.foss.export.SaveFormat;

import java.time.LocalDateTime;

try (Presentation pres = new Presentation()) {
    ICommentAuthor author = pres.getCommentAuthors().addAuthor("Alice", "A");
    ISlide slide = pres.getSlides().get(0);
    LocalDateTime now = LocalDateTime.of(2026, 1, 15, 12, 0, 0);
    IComment comment = author.getComments().addComment("Review note", slide,
            new PointF(2.0f, 3.0f), now);

    pres.save("comments.pptx", SaveFormat.PPTX);
}

Set Document Properties

import org.aspose.slides.foss.*;
import org.aspose.slides.foss.export.SaveFormat;

try (Presentation pres = new Presentation()) {
    IDocumentProperties props = pres.getDocumentProperties();
    props.setTitle("My Presentation");
    props.setSubject("Demo Subject");
    props.setAuthor("John Doe");
    props.setKeywords("demo, test");
    props.setCategory("Examples");

    pres.save("properties.pptx", SaveFormat.PPTX);
}

Apply an Outer Shadow Effect to a Shape

import org.aspose.slides.foss.*;
import org.aspose.slides.foss.drawing.Color;
import org.aspose.slides.foss.export.SaveFormat;

try (Presentation pres = new Presentation()) {
    ISlide slide = pres.getSlides().get(0);
    slide.getShapes().clear();
    IAutoShape shape = slide.getShapes().addAutoShape(ShapeType.RECTANGLE, 100, 100, 200, 100);

    IEffectFormat ef = shape.getEffectFormat();
    ef.enableOuterShadowEffect();
    IOuterShadow shadow = ef.getOuterShadowEffect();
    shadow.setBlurRadius(10);
    shadow.setDirection(315);
    shadow.setDistance(8);
    shadow.getShadowColor().setColor(Color.fromArgb(128, 0, 0, 0));

    pres.save("shadow.pptx", SaveFormat.PPTX);
}

Add Speaker Notes to a Slide

import org.aspose.slides.foss.*;
import org.aspose.slides.foss.export.SaveFormat;

try (Presentation pres = new Presentation()) {
    ISlide slide = pres.getSlides().get(0);
    INotesSlide notes = slide.getNotesSlideManager().addNotesSlide();
    notes.getNotesTextFrame().setText("Speaker notes");

    pres.save("notes.pptx", SaveFormat.PPTX);
}

Embed an Image as a Picture Frame

import org.aspose.slides.foss.*;
import org.aspose.slides.foss.export.SaveFormat;

try (Presentation pres = new Presentation()) {
    IPPImage img = pres.getImages().addImage(imageBytes);
    pres.getSlides().get(0).getShapes().addPictureFrame(
            ShapeType.RECTANGLE, 50, 50, 100, 100, img);

    pres.save("picture.pptx", SaveFormat.PPTX);
}

Clone a Slide

import org.aspose.slides.foss.*;

try (Presentation pres = new Presentation()) {
    ISlide slide = pres.getSlides().get(0);
    slide.getShapes().addAutoShape(ShapeType.RECTANGLE, 50, 50, 200, 100);
    pres.getSlides().addClone(slide);
    // pres.getSlides().size() is now 2
}

Open an Existing Presentation

import org.aspose.slides.foss.Presentation;
import java.nio.file.Path;

try (Presentation pres = new Presentation(Path.of("Presentation.pptx").toString())) {
    // pres.getSlides().size() reflects the real slide count in the file
}

Save a Presentation to an In-Memory Stream

import org.aspose.slides.foss.Presentation;
import org.aspose.slides.foss.export.SaveFormat;
import java.io.ByteArrayOutputStream;

try (Presentation pres = new Presentation()) {
    ByteArrayOutputStream buf = new ByteArrayOutputStream();
    pres.save(buf, SaveFormat.PPTX);
}

Format a Text Portion's Font Size, Weight, and Color

import org.aspose.slides.foss.*;
import org.aspose.slides.foss.drawing.Color;
import org.aspose.slides.foss.export.SaveFormat;

try (Presentation pres = new Presentation()) {
    IAutoShape shape = pres.getSlides().get(0).getShapes()
            .addAutoShape(ShapeType.RECTANGLE, 50, 50, 400, 150);
    shape.addTextFrame("Formatted text");
    IPortionFormat fmt = shape.getTextFrame().getParagraphs().get(0)
            .getPortions().get(0).getPortionFormat();
    fmt.setFontHeight(24);
    fmt.setFontBold(NullableBool.TRUE);
    fmt.getFillFormat().setFillType(FillType.SOLID);
    fmt.getFillFormat().getSolidFillColor().setColor(Color.fromArgb(255, 0, 70, 127));

    pres.save("text.pptx", SaveFormat.PPTX);
}

Create a Table and Set Cell Text

import org.aspose.slides.foss.*;
import org.aspose.slides.foss.export.SaveFormat;

try (Presentation pres = new Presentation()) {
    ITable table = pres.getSlides().get(0).getShapes()
            .addTable(50, 50, new double[]{120, 120, 120}, new double[]{40, 40});
    table.getRows().get(0).get(0).getTextFrame().setText("Name");
    table.getRows().get(0).get(1).getTextFrame().setText("Value");

    pres.save("table.pptx", SaveFormat.PPTX);
}

Save a Subset of Slides

save(path, slides, format) takes a zero-based slide-index array; repeats are ignored and the slides kept stay in document order:

import org.aspose.slides.foss.Presentation;
import org.aspose.slides.foss.export.SaveFormat;

try (Presentation pres = new Presentation("deck.pptx")) {
    pres.save("first-and-third.pptx", new int[]{0, 2}, SaveFormat.PPTX);
}

API Reference

The primary entry point is Presentation, which owns an ISlideCollection of Slide objects; each slide exposes an IShapeCollection of Shape-derived objects (AutoShape, Connector, Table, PictureFrame) built through ShapeCollection's addAutoShape(), addConnector(), addTable(), and addPictureFrame() methods.

Foss

Class	Description
AdjustValue	Represents a single geometry adjustment value backed by an OOXML `` element.
AdjustValueCollection	Represents a collection of shape's adjustments backed by an OOXML `` element.
AutoShape	Represents an AutoShape.
BaseHandoutNotesSlideHeaderFooterManager	Represents abstract base class for handout and notes slide header/footer managers.
BasePortionFormat	Common text portion formatting properties.
BaseShapeLock	Base class for shape locks.
BaseSlide	Represents common data for all slide types.
Blur	Represents a Blur effect that is applied to the entire shape, including its fill.
BulletFormat	Represents paragraph bullet formatting properties.
Camera	Represents 3D camera settings.
Cell	Represents a cell of a table.
CellCollection	Represents a collection of cells.
CellFormat	Represents format of a table cell.
Color	Immutable value type representing an ARGB color.
ColorFormat	Represents a color used in a presentation.
Column	Represents a column in a table.
ColumnCollection	Represents collection of columns in a table.
ColumnFormat	Represents formatting properties of a table column.
Comment	Represents a comment on a presentation slide.
CommentAuthor	Represents an author of comments.
CommentAuthorCollection	Represents a collection of comment authors in a presentation.
CommentCollection	Represents a collection of comments of one author.

Interfaces

Class	Description
IAdjustValue	Represents a geometry shape adjustment value.
IAdjustValueCollection	Represents a collection of shape adjustment values.
IAutoShape	Represents an AutoShape.
IBaseHandoutNotesSlideHeaderFooterManager	Represents base interface for handout and notes slide header/footer managers.
IBaseHeaderFooterManager	Represents base interface for header/footer managers.
IBasePortionFormat	Represents common text portion formatting properties.
IBaseSlide	Represents common data for all slide types.
IBaseSlideHeaderFooterManager	Represents base interface for slide header/footer managers that manage footer, slide number, and date-time placeholders.
IBlur	Represents a Blur effect that is applied to the entire shape, including its fill.
IBulkTextFormattable	Represents an object with the possibility of bulk setting child text elements' formats.
IBulletFormat	Represents paragraph bullet formatting properties.
ICamera	Represents Camera.
ICell	Represents a cell in a table.
ICellCollection	Represents a collection of cells.
ICellFormat	Represents format of a table cell.
IColorFormat	Represents a color used in a presentation.
IColumn	Represents a column in a table.
IColumnCollection	Represents collection of columns in a table.
IColumnFormat	Represents format of a table column.
IComment	Represents a comment on a presentation slide.
ICommentAuthor	Represents a comment author in a presentation.

Enumerations

Class	Description
BevelPresetType	Constants which define 3D bevel of shape.
BulletType	Represents the type of the extended bullets.
CameraPresetType	Constants which define camera preset type.
ColorType	Represents different color modes.
FillBlendMode	Determines blend mode.
FillType	Specifies the interior fill type of various visual objects.
FontAlignment	Represents vertical font alignment.
GradientDirection	Represents the gradient style.
GradientShape	Represents the shape of gradient fill.
LightRigPresetType	Constants which define light preset types.
LightingDirection	Constants which define light directions.
LineAlignment	Represents the lines alignment type.
LineArrowheadLength	Represents the length of an arrowhead.
LineArrowheadStyle	Represents the style of an arrowhead.
LineArrowheadWidth	Represents the width of an arrowhead.
LineCapStyle	Represents the line cap style.
LineDashStyle	Represents the line dash style.
LineJoinStyle	Represents the lines join style.
LineStyle	Represents the style of a line.
MaterialPresetType	Constants which define material of shape.
NullableBool	Represents triple boolean values.
NumberedBulletStyle	Represents the style of the numbered bullets.
PatternStyle	Represents the pattern style.
PictureFillMode

---

Detailed Member Reference

• Presentation — the root object; owns slides, images, comment authors, and document properties.
  • Presentation(), Presentation(path), Presentation(in) -> Presentation
  • getSlides() -> ISlideCollection, getImages() -> IImageCollection, getCommentAuthors() -> ICommentAuthorCollection
  • getDocumentProperties() -> IDocumentProperties, getLayoutSlides() -> IGlobalLayoutSlideCollection, getMasters() -> IMasterSlideCollection
  • save(path, format) -> void, save(stream, format) -> void, dispose() -> void
• SlideCollection — the real ISlideCollection implementation returned by Presentation.getSlides().
  • get(index) -> ISlide, size() -> int, addClone(sourceSlide) -> ISlide, addEmptySlide(layout) -> ISlide, insertEmptySlide(index, layout) -> ISlide, removeAt(index) -> void, indexOf(slide) -> int
• ShapeCollection — the real IShapeCollection implementation returned by Slide.getShapes().
  • addAutoShape(shapeType, x, y, width, height) -> IAutoShape, addConnector(shapeType, x, y, width, height) -> IConnector
  • addTable(x, y, colWidths, rowHeights) -> ITable, addPictureFrame(shapeType, x, y, width, height, image) -> IPictureFrame
  • get(index) -> IShape, size() -> int, remove(shape) -> void, removeAt(index) -> void, clear() -> void, reorder(index, shape) -> void
• AutoShape — a preset-geometry shape (rectangle, ellipse, and every other ShapeType).
  • getShapeType() -> ShapeType, addTextFrame(text) -> ITextFrame, getTextFrame() -> ITextFrame, getFillFormat() -> IFillFormat, getLineFormat() -> ILineFormat, getEffectFormat() -> IEffectFormat, getThreeDFormat() -> IThreeDFormat
• Connector — a shape-to-shape connector line.
  • getStartShapeConnectedTo() -> IShape, , ,

Documentation & Resources

This library mirrors the naming of the commercial Aspose.Slides for Java product, so that product's own documentation is often the fastest way to understand what a shared type name means — it describes a much larger API, so check Scope and Limitations before relying on anything read there.

• Getting started guide — setup, core concepts, and step-by-step guides for Aspose.Slides FOSS for Java.
• How-to guides & FAQ — task-focused how-to articles for common presentation operations.
• Full API reference — the complete, browsable reference (the API Reference section above covers the essentials).
• Contributor guide — build commands, core concepts, and import patterns for working on the source.
• Publishing guide — how releases are built and published to Maven Central. Searching search.maven.org itself finds nothing — a limitation of that particular search index, not of the release — but the artifact resolves normally from repo1.maven.org and lists correctly on central.sonatype.com.
• Found a bug or have a feature request? Open an issue on GitHub.

Choosing an Edition

There are four editions of this library and they are not interchangeable. Three of them — .NET, Java, and C++ — are the same design in three languages; Python is a larger and different one.

	.NET	Java	C++	Python
Create, open, round-trip, save	yes	yes	yes	yes
Text, tables, connectors, fills, all 8 effects, 3-D	yes	yes	yes	yes
Notes and classic comments	yes	yes	yes	yes
Threaded comment part	no	yes	no	yes
Save to a stream	yes	yes	no	yes
Add a picture from a stream	yes	yes	no	yes
Clone a slide, with its text	yes	yes	partial	yes
Clone a master	yes	no	no	yes
Sections	yes	no	no	no
Charts, animations, transitions, themes, backgrounds, group shapes, hyperlinks	no	no	no	yes
Formats save writes	3	3	6	7
Default slide size of a new deck	4:3	4:3	4:3	16:9

If you need charts, animations, transitions, themes, backgrounds, group shapes, or hyperlinks, none of them exist in this edition — use the Python one. If you need sections, only the .NET edition has them. Code written against the Python examples does not port here, and a new deck is not even the same shape.

• Aspose.Slides FOSS for .NET
• Aspose.Slides FOSS for C++
• Aspose.Slides FOSS for Python

When you want the commercial product instead: if you need to render or convert — PDF, images, HTML, thumbnails — or need charts, SmartArt, animations, OLE objects, or macro-enabled files, or need a supported product with a licence behind it, none of that is here and none of it is planned in this repository. This library is the right choice when you are reading and writing .pptx and want an MIT-licensed dependency that brings nothing else with it.

Scope and Limitations

This section is the point of this file. Nothing here is a "coming soon"; it is what the API does not contain today.

• Not in the public API: charts (no IShapeCollection.addChart); SmartArt, OLE objects, video, and audio (not modelled); animations and slide transitions (no ISlide.getTimeline, no ISlide.getSlideShowTransition); group shapes (no IShapeCollection.addGroupShape — no shape can hold child shapes); hyperlinks (no setHyperlinkClick on a shape or a text portion); sections (no IPresentation.getSections); slide backgrounds (no ISlide.getBackground); themes (no IPresentation.getMasterTheme); slide size (no IPresentation.getSlideSize — a new deck is 4:3, cx="9144000" cy="6858000" type="screen4x3", with no supported way to change it); and rendering or conversion of any kind (no PDF, HTML, SVG, image, or text export); VBA macros, digital signatures, and encryption are not modelled either.

• A known defect: cloning a master. getMasters().addClone(...) returns and the collection then reports a size of 2 — but the saved package contains one <p:sldMasterId> and one ppt/slideMasters/slideMaster1.xml. The clone never reaches the file, and nothing reports a problem. Do not rely on it.

• Save formats: SaveFormat declares 25 values. save() writes three of them — PPTX, PPSX, and POTX, each a genuinely different package with its own main-part content type — and raises UnsupportedOperationException for the other 22 (PPT, PDF, XPS, TIFF, ODP, PPTM, PPSM, POTM, HTML, HTML5, SWF, OTP, PPS, POT, FODP, GIF, MD, XML, SVG, JPEG, PNG, BMP); it never writes a package under a name that claims to be a format it did not produce, and nothing is left on disk when it refuses. The macro-enabled formats are refused because their content type declares a VBA project this library does not write. The refusal names the alternatives:

  Export format 'Pdf' is not supported. Writable formats are: Pptx, Ppsx, Potx
  

  Give the file the extension its format uses — save("deck.pptx", SaveFormat.POTX) writes a correct template that PowerPoint refuses to open, because the content type says template and the name says presentation.

These limitations don't apply to Aspose.Slides for Java — Enterprise Edition, which adds full format export (PDF, HTML, XPS, images, and more), charts, animations, VBA macro support, and every other capability outside this FOSS build's scope.

Development and Testing

git clone https://github.com/aspose-slides-foss/Aspose.Slides-FOSS-for-Java.git
cd Aspose.Slides-FOSS-for-Java
mvn verify -Dgpg.skip=true

JDK 21 or later and Maven are required; the build refuses to start otherwise. That one command runs the whole test suite — unit tests under src/test/java plus the integration tests under tests/integration and the conformance tests under tests/conformance (both wired in as additional test source directories via the build-helper-maven-plugin in pom.xml) — and builds the jar, the sources jar, the javadoc jar, and a CycloneDX SBOM into target/. The conformance tests unzip the produced .pptx and assert on the package itself, never on what this library reads back — the same rule CONTRIBUTING.md states explicitly: a writer fix ships with a test that asserts on the produced package, not on what the library reads back. -Dgpg.skip=true skips artifact signing, which is part of verify and needs the release key.

Compiler warnings fail the build (-Xlint:all), and so does a javadoc error. Two builds of the same source produce byte-identical jars — project.build.outputTimestamp fixes the build date instead of taking it from the clock, and CI proves it by building twice and comparing the hashes.

Every push and every pull request runs that build on Linux, Windows, and macOS, on Java 21 and Java 25 (.github/workflows/build.yml). The jar, sources jar, javadoc jar, and SBOM from each run are downloadable from the run's page.

Releases publish to Maven Central via maven-central-release.yml — see PUBLISHING.md for the full release process.

Pull requests are welcome — CONTRIBUTING.md explains the build and the test suites. By participating you agree to the Code of Conduct. Changes between releases, including behaviour changes and removed API, are in CHANGELOG.md.

Do not report a vulnerability in a public issue — SECURITY.md has the reporting route.

License

This project is licensed under the MIT License. The MIT License permits use, copying, modification, distribution, sublicensing, and commercial use, provided its copyright and permission notice are retained. The software is provided without warranty.