Inkscape is a drawing tool with capabilities similar to Illustrator, Freehand, and CorelDraw that uses the W3C standard scalable vector graphics format (SVG). The supported SVG features include basic shapes, paths, text, markers, clones, alpha blending, transforms, gradients, and grouping. In addition, it supports Creative Commons meta-data, node-editing, layers, complex path operations, text-on-path, and SVG XML editing. It also imports several formats like EPS, Postscript, JPEG, PNG, BMP, and TIFF and exports PNG as well as multiple vector-based formats.
Sketsa SVG Editor is a vector drawing application based on SVG. It allows users to create vector graphics that can be scaled and printed at any resolution, without losing detail or clarity. It features various tools for optimizing content creation, and includes a property palette, a DOM editor, a source editor, a resource editor, SVG-specific shape tools, transformation tools, and additional illustration tools. It uses SVG as its native file format.
DirectFB is a thin library that provides developers with hardware graphics acceleration, input device handling and abstraction, an integrated windowing system with support for translucent windows and multiple display layers on top of the Linux framebuffer device. It is a complete hardware abstraction layer with software fallbacks for every graphics operation that is not supported by the underlying hardware.
Tux Paint is a simple and entertaining drawing program geared towards young children. It has a simple interface, sound effects, and a cartoon character (Tux, the Linux penguin). Along with drawing brush strokes, lines and shapes, you can also enter text and place "rubber stamp" (or "sticker") images on the picture. Tux Paint is extensible, and could be useful in an educational environment (such as a grammar, elementary, or grade school). It's portable across numerous platforms, and runs well even on slower systems like the Pentium 133MHz.
Evolvotron is an interactive "generative art" application to evolve images/textures/patterns through an iterative process of random mutation and user-selection driven evolution. If you like lava lamps, and never got tired of the Mandelbrot set, this could be the software for you. It's implemented using Qt, and is multithreaded.
Gnofract 4D is a Gnome-based program to draw fractals. What sets it apart from other fractal programs (and makes it "4D") is the way that it treats the Mandelbrot and Julia sets as different views of the same four-dimensional fractal object. It contains a Fractint-compatible formula compiler, allowing it to draw an unlimited number of fractal types, using numerous coloring options.