XQuartz has an update for X11 on Mac. Remember to re-install this package after further updates to Mac OS X.
UPDATE: it’s been updated to 220.127.116.11 already.
GPULib enables IDL developers to access the high-performance capabilities of modern NVIDIA graphics cards without knowledge of CUDA programming.
TaskDL is a task-farming solution for IDL designed for problems with loosely-coupled, parallel applications where no communication between nodes of a cluster is required.
mpiDL is a library of IDL bindings for Message Passing Interface (MPI) used for tightly-coupled parallel applications.
The Remote Data Toolkit is a library of IDL routines allowing for easy access to various scientific data in formats such as OPeNDAP, HDF 5, and netCDF.
Modern IDL offers IDL programmers one place to look, for beginners and advanced users alike. This book also contains: a thorough tutorial on the core topics of IDL; a comprehensive introduction to the object graphics system; common problems and gotchas with many examples; advanced topics not normally found are discussed throughout the book: regular expressions, object graphics, advanced widget programming, performance, object-oriented programming, etc.
IDLdoc is an open source utility for generating documentation from IDL source code and specially formatted comments.
mgunit is an open source unit testing framework for IDL.
rIDL is an open source IDL command line replacement.
mglib is an open source library of IDL routines in areas of visualization, application development, command line utilities, analysis, data access, etc.