Inkscape is an open-source vector graphics editor similar to Adobe Illustrator, Corel Draw, Freehand, or Xara X. What sets Inkscape apart is its use of Scalable Vector Graphics (SVG), an open XML-based W3C standard, as the native format.
Features of Inkscape:
Object creation
Drawing: pencil tool (freehand drawing with simple paths), pen tool (creating Bézier curves and straight lines), calligraphy tool (freehand drawing using filled paths representing calligraphic strokes)
Shape tools: rectangles (may have rounded corners), ellipses (includes circles, arcs, segments), stars/polygons (can be rounded and/or randomized), spirals
Text tool (multi-line text, full on-canvas editing)
Embedded bitmaps (with a command to create and embed bitmaps of selected objects)
Clones ("live" linked copies of objects), including a tool to create patterns and arrangements of clones
Object manipulation
Transformations (moving, scaling, rotating, skewing), both interactively and by specifying exact numeric values
Z-order operations (raising and lowering)
Grouping objects ("select in group" without ungrouping, or "enter the group" making it a temporary layer)
Layers (lock and/or hide individual layers, rearrange them, etc; layers can form a hierarchical tree)
Alignment and distribution commands
Fill and stroke
Color selector (RGB, HSL, CMYK, color wheel, CMS)
Color picker tool
Copy/paste style
A gradient editor capable of multi-stop gradients
Pattern fills (bitmap/vectors)
Dashed strokes, with many predefined dash patterns
Path markers (ending, middle and/or beginning marks, e.g. arrowheads)
Operations on paths
Node editing: moving nodes and Bezier handles, node alignment and distribution, etc.
Converting to path (for text objects or shapes), including converting stroke to path
Boolean operations
Path simplification, with variable threshold
Path insetting and outsetting, including dynamic and linked offset objects
Bitmap tracing (both color and monochrome paths)
Text support
Multi-line text
Uses any installed outline fonts, including right-to-left scripts
Kerning, letterspacing, linespacing adjustments
Text on path (both text and path remain editable)
Text in shape (fill shape following stroke)
Rendering
Fully anti-aliased display
Alpha transparency support for display and PNG export
Complete "as you drag" rendering of objects during interactive transformations
Misc
Live watching and editing the document tree in the XML editor
PNG, OpenDocument Drawing, DXF, sk1, PDF, EPS and PostScript export formats and more
Command line options for export and conversions
Perfectly compliant SVG format file generation and editing