I've intended to announce this development at Drupalcon San Francisco but unfortunately the session on this was merged with a more general i18n session which was coupled by the ash cloud above Europe, so I could not go. Evidently, collaborative software translation is not a mainstream topic. On the other hand, I keep receiving requests of the general applicability of the tools Drupal.org uses about every two weeks, and this interest always amazes me. While the localization server tool used on localize.drupal.org grew out of needs of the Drupal community, the solutions were architected to be useful in a general purpose software translation environment. While the architecture was there, it was lacking useful UI controls to just run it as a generic software translation tool.
Existing non-Drupal users like the Gallery 2/3 project and the Musescore desktop app utilize custom data connector modules, which the localization server nicely supports, allowing for custom code to gather data for translation. Gallery even uses a custom Localization client port for clients to submit translations to the server, even though their software is not Drupal based. However, translating arbitrary software without writing your custom connector code was not possible earlier.