There are many ways to create a picture in TeX , including using:
"TeXdraw consists of a set of TeX macros that create line drawings and otherfigures. The drawing commands generate PostScript code."
The manual: ps.gz; local mirror: ps.gz.
"Graph-TeX is actually a Perl library (graphtex.pl) along with a preprocessor (gt) which can be used to generate TeXdraw commands producing graphs and related diagrams in side a TeX environment. "
"XY-pic is a package for typsetting graphs and diagrams using... [TeX ]... XY-pic works with most of the many formats available, e.g., Plain TeX , LaTeX ,.... "
XY-pic is implemented using standard TeX and Metafont, so is not limited to PostScript output.
See the XY-pic documentation on CTAN for further information; local mirror — user guide: dvi, ps; reference manual: dvi, ps.
The mfpic package is a set of macros for METAFONT and TeX which incorporate Metafont-drawn pictures into a TeX file.
The manual; local mirror: tex, dvi, ps.gz.
PiCTeX is a set of macros for drawing diagrams and pictures. The macros are freely available; however the manual is not free — it is available only from Personal TeX Inc, the vendors of PCTeX.
Zdenek Wagner (wagner@csearn.bitnet --- preferred, wagner@earn.cvut.cs) has written a document, Simple drawings with METAFONT which describes how to make simple drawings with METAFONT and inclusion into LaTeX documents. Its intended for the "slightly advanced", though a knowledge of [the contents of] the METAFONT book is not needed; alternatively access ISD's local copy.
"The MetaPost system is based on Knuth's Metafont... MetaPost is a graphics language like Metafont, but with new primitives for integrating text and graphics and for accessing special features of PostScript... "
"While MetaPost could be used as a tool for generating PostScript fonts, the intended application is to generate figure for TeX and troff documents. The figures can be integrated in to a TeX document via... dvips. "
xjpdraw is a GUI graphics editor, the output of which is a combination of LaTeX source code and PostScript.
The users' manual: ps.gz; local mirror: ps.gz.
Xfig is a GUI drawing tool which can export to LaTeX source code.
PSTricks is a collection of Postscript-based TeX macros that is compatible with most TeX macro packages, including Plain TeX and LaTeX . PSTricks gives you color, graphics, rotation, trees, overlays...
For more details, including the manual, see the PSTricks website; local mirror: Part One ps.gz, Part Two ps.gz, Part Three ps.gz, Part Four ps.gz.