Arabeske is a special kind of vector drawing software. It has a limited set of shapes but is extremely specialised towards complex symmetric interlaced drawings, like those traditionally found in Arabic architecture. It is not a texture editor, but rather a pattern generator. It exports in EPS, PNG, and POV-Ray formats.
Dia is a program for creating diagrams of all kinds. The current version can do UML class diagrams, Entity-Relationship modeling, network diagrams, and much more. The engine is very flexible and dynamically loads diagram-types from disk. It stores diagrams in an XML format, but can read and write a number of different formats.
DiaCanvas is a generalized version of the drawing canvas used by DIA. It extends some features used by DIA and adds new ones, while preserving as many of the original features as possible. This project is no longer actively maintained. It is suggested that you try DiaCanvas2 instead.
mvComicsMaker (mvCM) is a free graphics editor for creating bitmap and vector animations under Linux. mvCM allows you to use bitmaps together with vector graphics and combine indexed pictures with true color pictures. The final animation may be rendered into MVA, FLC, BMP, or PNG format. The main goal of mvCM is to help calculate frames of animation.