In software development (as in many other fields, like paper or thesis writing ;-)), you often need a revision control software to effectively manage all the changes made to your source code (or sections and chapters). It’s even more important if you work with other people on the same files, on different versions of the same sources, with people in different locations and with different systems.
The problem I currently try to solve (or, at least, try to bring a solution to) is the following … The system doesn’t initially use any revision control software. People are able to edit any file they want, one at a time (file locking which is very annoying). Basically, there is only one version of a file per project: the current one. If another project tries to merge the same file from another project, someone has to manually review all the lines in order to see what should remain and what should be left. In order to reach a previous version of a file, you have to manually remove lines marked with the patch reference at a specific location on some lines (it does work in some programming languages and not at all in all others). In fact, a rudimentary revision control system exists but it’s completely outside the development environment. When a file is modified, it’s name is entered in a “patch system” with the reason why it was modified (when you are lucky). If you forget to enter its name, the system can’t do anything for you (since it’s not aware of anything).
...