*tcl-hwloc*
        is a binding to "hwloc", the "Portable Hardware Locality".

In hwloc's words:

        The Portable Hardware Locality (hwloc) software package
        provides a portable abstraction (across OS, versions,
        architectures, ...) of the hierarchical topology of modern
        architectures, including NUMA memory nodes, sockets, shared
        caches, cores and simultaneous multithreading. It also gathers
        various system attributes such as cache and memory
        information. It primarily aims at helping applications with
        gathering information about modern computing hardware so as to
        exploit it accordingly and efficiently.

This functionality is now accessible from within Tcl as well.

        Please give thanks to George Andreou, who wrote it during this
        year's Google's Summmer Of Code.

The project can be found at

        http://code.google.com/p/tcl-hwloc/

Building it assumes that 'hwloc' is already installed on your
system. You need hwloc 1.2 or higher.

The package is currently at only version 0.2 because I hope to get
more feedback from users regarding the exposed API before making it
final.

Examples of use:

*       Take a thread pool, and size the pool to match the number of
        CPU(s) in the system (or maybe a small multiple thereof).

*       Force a particular thread to run on a specific CPU (core,
        processing unit, etc.). I.e. spread the load, if there are
        many threads.

*       Simply use it write a Tcl/Tk equivalent of hwloc's "lstopo"
        command.

Hopefully you can think of more things this is useful for.

For background, this is what became of the withdrawn TIP 377

        http://tip.tcl.tk/377.html
        Portably Determining the Number of Processors in the System