Troy Henderson's MetaPost Previewer - Submit MetaPost code on the web page and get the result presented as EPS or PDF instantly. - http://www.tlhiv.org/cgi-bin/MetaPostPreviewer/index.cgi
Metapost - Metapost links, compiled by Luc Devroye. - http://cg.scs.carleton.ca/~luc/metapost.html
FeatPost Examples - FeatPost is an extension of the MetaPost language, works in three dimensions and has several features to facilitate the production of physics schemes. - http://matagalatlante.org/nobre/featpost/doc/featexamples.html
MPS2EPS - Shell script that converts a given MPS to a self-contained EPS file with the necessary fonts included. - http://www.ida.liu.se/~joned/download/mps2eps/
Marc's MetaPost Page - Links to a selection of MetaPost sources. - http://www.cs.ucc.ie/~dongen/mpost/mpost.html
MetaPost Arrows and Braces - A package for arrows and braces in the computer modern style. - http://www.student.nada.kth.se/~f91-tek/cm_arrows.html
Papers about MetaPost - MetaPost Publications. - http://cm.bell-labs.com/who/hobby/mppubs.html
MetaPost - A powerful graphics language based on Knuth's METAFONT, but with PostScript output and facilities for including typeset text. Public domain. - http://cm.bell-labs.com/who/hobby/MetaPost.html