UMbase releases are aligned to whole numbers. In February 2025, UMbase was forked from a software system called Songfish, and began using a simplified release numbering system. We no longer use "point releases."

Releases

The current stable release of UMbase is 431 (Calpurnia).

UMbase is developed using the principles of rapid application development (RAD), so there are frequent releases/updates – in fact, there is a new build of UMbase, on average, about every other day^[1] - 1675 total builds. There have been 431 production releases of UMbase, with an average of roughly 5 days between releases^[2].

Why Codenames?

Simply put, because they're fun. Every release has a codename and codenames generally follow a theme for several releases. Codenames are not political statements. Here are some of the subjects after which UMbase releases have been named.

Versions	Number of Releases	Code name theme
415 – 431	17	Shakespeare Characters
366 – 414	49	Spices
9.0 – 9.93	94	World Capitols
8.0 – 8.47	48	African Countries
7.0 – 7.117	118	Elements of the Periodic Table
6.0 – 6.5	6	Municipalities of Greenland
5.0 – 5.7	8	Canadian Cities (Reprise)
4.0 – 4.5	6	Iron Chef Judges
3.24 – 3.48	25	Fish from A-Z
3.0 – 3.23	24	Fish, Alphabetically
2.0 – 2.6	7	Asian Capitols
1.25 – 1.27	3	Candian Capitols
1.10 – 1.24	15	European Capitols
0.9 – 1.9	11	Iron Chefs