I am pleased to announce the first public version the ordereddict module. From the blurb on ordereddict's home-page: This is an implementation of an ordered dictionary with Key Insertion Order: updates of values do not affect the position of the key. It implementation is directly derived from dictobject.c and its speed is 5-10% slower than dict() and 5-9 times faster than Larosa/Foord excellent pure Python implemention. This module has been tested under: Ubuntu 7.04, gcc : Python 2.5.1 Ubuntu 7.04, gcc : Python 2.4.4 Ubuntu 6.06, gcc : Python 2.5.1 Windows XP, Visual Studio 2003: Python 2.5.1 (see below) ordereddict's home on the web is at http://www.xs4all.nl/~anthon/Python/ordereddict there you also find the links where the source can be downloaded. The download includes relatively complete tests for all of ordereddict's functionality (all of dict() plus for now: .index(), .reverse(), .insert()) I hope this is useful and appreciate any feedback Anthon van der Neut -- Windows specific compilation problem: In order for things to link under Visual Studio 2003, I had to #ifdef out the call _PyObject_GC_TRACK. I am not sure why this caused a problem and had hoped that distutils would take care of these kind of linker issues. Until this is resolved, or confirmed as a non-issue please do not use this code in anything running for a longer period of time and relying on garbagecollection to operate correctly.