I have created a SqueakSource project called SystemTracing to serve as a repository for the various SystemTracer implementations that have appeared in and around Squeak images since Squeak 1.22. The intent is to make these implementations loadable in modern images, and to provide a Monticello repository for new development. MCHttpRepository location: 'http://www.squeaksource.com/SystemTracing' user: 'squeak' password: 'squeak' All classes and package extension methods have been recategoried to SystemTracing but are otherwise unmodified to the extent possible. The recategorizing was done by hand-editing the original change sets. The archive includes historical versions that appeared in early Squeak images, as well as loadable versions of the SystemTracer2 that is catalogued on SqueakMap. There is an entry for the SystemTracer64 that was used to produce the first 64-bit Squeak image, and recent updates that will enable 64-bit images to be traced from modern Squeak and Pharo images (there is more work to be done here). Developer access is provided for Stephen Pair, John M McIntosh, Andreas Raab, Eliot Miranda, Jannik Laval, Ian Piumarta. If anyone else should be added as developer, please speak up. All future contributions to this archive are required to be MIT licensed. Dave