Vitdom: Yea this is probably off-topic, but probably no better topic title then something concerning the Opposition Nymph! And the fact that I enjoy open source seem to go hand in hand.
From what I've seen so far and I've only written some random small snippets of the SQF syntax scripting, compared to C and Unix/Linux SH/Bash scripting; the SQF scripting language utilized by the ARMA series of games is called SQF, or a scripting language having a SQF syntax. (When using text editors, you'll want to use the SQF syntax for coloring your text or script within the editor.)
It does not appear that there is an all in one inclusive source of information concerning the language and functions used within each game version, but spread about Bohemia's domains.
If you have questions, people usually point you towards Bohemia Interactive's forums. Usually most developers are grateful and willing to help most people. And if you have an "Oh my God" great idea, you may see the idea readily employed. Just be advised some people you might come across do get hostile within the forums, and probably best to just avoid them.
Following are my URLS for referencing:
(ie. The Developer Changelog may include function naming conversions, and maybe needed to update your scripts.)
After reading quite a bit of the already written scripting, I would suggest having some experience at writing SH/Bash and even C programs, as the scripting language is reminiscent of a stripped-down Sh or C shell. Be consistent with your spacing and know how the computer reads code. Use good variable naming and please please make sure you comment your code well! I would suggest ignoring the people claiming too many comments or statements not needing comments, as comments will not or should not slow the computer any. (I guess some people enjoy unreadable code, as it keeps them employed or fear becoming unemployed.)
Also within the 3D game editor, I think press ESC and you'll be given a menu for finding functions and/or classes. I've found this method difficult to use and maybe better streamlined when they deploy the Eden editor. But this method of finding the most current functions or classes to be the most accurate, but lacks the documentation similar to the above URL's.
Oh, and do not forget to make back-ups of your scripts. Use of a version system (ie. CVS, SVN, Git, ...) or simply backup your scripts be using a date suffix such as script-20151125.sqf. (On Unix/Linux, we just do script.sqf.20151125.) When packaging, make sure your file are contained within a version or dated suffixed sub-folder. (ie. MyScript-20151125/)
I included a few Windows related solutions to some hiccups I've seen within past Windows related packages.
Good luck!