Here are the classes, structs, unions and interfaces with brief descriptions:
[detail level 123]
  ipe | |
   Color | An absolute RGB color |
| Tiling | A tiling pattern |
 Gradient | A gradient pattern |
| Layout | Layout of a Page |
| TextPadding | Padding for text bounding box |
| Effect | Effect that Acrobat Reader will show on page change |
| Repository | Repository of strings |
| Attribute | An attribute of an Ipe Object |
| AllAttributes | Collection of all object attributes |
| String | Strings and buffers |
| Fixed | Fixed point number with three (decimal) fractional digits |
| Lex | Lexical analyser. Seeded with a string |
| Buffer | A memory buffer |
| Stream | Abstract base class for output streams |
| TellStream | Adds position feedback to IpeStream |
| StringStream | Stream writing into an String |
| FileStream | Stream writing into an open file |
| DataSource | Interface for getting data for parsing |
| FileSource | Data source for parsing from a file |
| BufferSource | Data source for parsing from a buffer |
| Platform | Platform dependent methods |
| Bitmap | A bitmap |
| Document | The model for an Ipe document |
| ObjectFactory | Factory for Ipe leaf objects |
| Angle | A double that's an angle |
| Vector | Two-dimensional vector |
| Rect | Axis-parallel rectangle (which can be empty) |
| Line | A directed line |
| Segment | A directed line segment |
| Bezier | A cubic Bezier spline |
| Linear | Linear transformation in the plane (2x2 matrix) |
| Matrix | Homogeneous transformation in the plane |
| Arc | An arc of an ellipse |
| Group | The group object |
| Image | The image object |
| ImlParser | XML Parser for Ipe documents and style sheets |
| Latex | Object that converts latex source to PDF format |
| IpeletHelper | Service provider for Ipelets |
| IpeletData | Information provided to an ipelet when it is run |
| Ipelet | Abstract base class for Ipelets |
| Object | Base class for all Ipe objects, composite or leaf |
| Visitor | Base class for visitors to Object |
| Page | An Ipe document page |
| Painter | Interface for drawing |
| Path | The path object (polylines, polygons, and generalizations) |
| PdfObj | Abstract base class for PDF objects |
| PdfNull | The PDF null object |
| PdfBool | The PDF bool object |
| PdfNumber | The PDF number object |
| PdfString | The PDF string object |
| PdfName | The PDF name object |
| PdfRef | The PDF reference object (indirect object) |
| PdfArray | The PDF array object |
| PdfDict | The PDF dictionary and stream objects |
| PdfToken | A PDF lexical token |
| PdfParser | PDF parser |
| PdfFile | All information obtained by parsing a PDF file |
| PdfPainter | |
| PdfWriter | Create PDF file |
| PsPainter | |
| PsWriter | |
| Reference | The reference object |
| PdfResources | All the resources needed by the text objects in the document |
| CurveSegment | A segment on an SubPath |
| SubPath | A subpath of a Path |
| Ellipse | An ellipse subpath |
| ClosedSpline | A closed B-spline curve |
| Curve | Subpath consisting of a sequence of CurveSegment's |
| Shape | A geometric shape, consisting of several (open or closed) subpaths |
| Snap | Performs snapping operations, and stores snapping state |
| Symbol | A symbol is a named object defined in an ipe::StyleSheet |
| StyleSheet | A style sheet maps symbolic names to absolute values |
| Cascade | A cascade of style sheets |
| Text | The text object |
| Tool | Abstract base class for various canvas tools |
| BitmapFinder | A visitor that recursively scans objects and collects all bitmaps |
| BBoxPainter | Paint objects using this painter to compute an accurate bounding box |
| A85Stream | Filter stream adding ASCII85 encoding |
| Base64Stream | Filter stream adding Base64 encoding |
| DeflateStream | Filter stream adding flate compression |
| A85Source | Filter source adding ASCII85 decoding |
| Base64Source | Filter source adding Base64 decoding |
| InflateSource | Filter source adding flate decompression |
| XmlAttributes | Stores attributes of an XML tag |
| XmlParser | Base class for XML stream parsing |
| CairoPainter | Ipe Painter using Cairo and Freetype as a backend |
| Face | A typeface (aka font), actually loaded (from a font file or PDF file) |
| Fonts | Provides the fonts used to render text |
| Thumbnail | |
| CanvasObserver | |
| CanvasBase | |
| Canvas | A widget (control) that displays an Ipe document page |
| PageSelector | A Qt widget that displays a list of Ipe pages |
| PanTool | A tool for panning the canvas |
| SelectTool | A tool for selecting objects |
 TransformTool | A tool for transforming the selected objects on the canvas |
| Canvas |