Base of Operations is a series of executables, put together by Tricob. As the title indicates, they were meant as starter packs for modders who wanted to try their hand on making a mod, but may have had difficulty or no interest in altering the source code.
Features found in the final version include seamless levels, enabling or disabling of Read This!, customized sign-on screens, 128+ doors and in-game messages.
The final release, which came out on New Year's Day 2012 featured the original Wolfenstein and Spear of Destiny EXE's with either seamless levels enabled or disabled, with or without Read This! and various mixtures thereof.
The set eventually morphed into MyMod4SDL.