• GAMS home page
• Class Canvas
• LibraryThing for class reference books
• SMU ebook of Model Building in Mathematical Programming, H. Paul Williams, Wiley, 1999 (NOTE: if you check it out noone else can use it!)
• Operations Research: the Science of Better
• Sci.op-research newsgroup
• INFORMS - the OR professional society

Software sources:

• OR Tooklit for solving small problems
• COIN-OR open source initiative
• NEOS server, for solving models submitted over the Internet
• Decision tree for optimization software
• INFORMS Resources: Software
• Animated LP Applet demo for 2D LPs
• OpenSolver for Excel

Reference Articles:

• Maxims for Modelers, Art Geoffrion

Commercial Modeling Languages:

• AIMMS
• AMPL
• GAMS
• LINGO
• Matlab’s optimization toolbox
• MPL
• OPL/Cplex Studio
• OptimJ
• RiverLogic Enterprise Optimizer
• SAS/OR
• Xpress-Mosel

Open Source Modeling Systems

• GNU LP kit 
• Pyomo
• COIN-OR  (11 projects)