Sword of Moonlight/Ex is an effort to restore and extend Sword of Moonlight through a series of open-source software initiatives. The / in the formal title follows the convention of GNU/Linux. Where /Ex or with Ex stands for inclusion of the Ex codebase: an abstraction layer for restoring and extending older Direct X games and software (in reality Ex has always evolved alongside Sword of Moonlight/Ex).
The single largest component of Sword of Moonlight/Ex is the Sword of Moonlight Extension Library. The library maps Ex to Sword of Moonlight (and sometimes vice versa) while not facilitating a number of services peculiar to Sword of Moonlight. Since 2013 the name of the library has changed to Sword of Moonlight Extended Warranty. The reason for the change was first and foremost to not monopolize the broad concept of "extension" as originally implied. But also the project's scope narrowed to purely playing games; made possible by delegating its roles as a modular library to related projects.
Ex is a play on words mirroring Microsoft's many extended Win32 APIs distinguished by having a camel-case Ex tacked onto the end. It is not to be confused with From Software's King's Field EX mobile phone game. The choice was constrained to the need for a 5 letter file name for the Extension Library. SomEx.dll was chosen because it can be written over the smallest Direct X library file names, DDraw.dll for instance. In retrospect "Ex" has proven an interesting jumping off point for much fun with words. The semi-official motto for Ex is "Extend Experiment & Exchange", where the & itself is an Ex stylized rendition of Et. Example and so on, the "word mine" is bottomless for now.
Presently, it is practical to omit /Ex in discussion of Sword of Moonlight. Only because Sword of Moonlight, for all intents and purposes, is unable to function independently of /Ex or by any other means.