These are promoted development releases that have more stable feature-sets, have undergone more testing, and have shown themselves to be more generally stable and usable. They also include binaries. Use these for more production-oriented work or more stable development.
These are development releases of the mainline development TBB source code base. They pass nightly testing, but they are not guaranteed to be as stable and robust as other types of releases. As of December, 2007 they no longer include binaries. Use these to see the latest features as they are being worked on, or to obtain bug fixes faster.
Only the source code is provided for development releases, to obtain installation packages use the stable releases.
These are additional downloads that may be useful in addition to the Intel® Threading Building Blocks software downloads.
These are the community contributions to the open source project.