FCS is a computer program written primarily for software developers as a tool for advanced patching.
The process of modifying(patching) folders and files is called flavouring. In order to flavour a project, FCS may use a series of techniques like: using a designed order to apply changes, use of symbols and macros on the fly, internal scripting, executing external programs which may be stored within the flavouring file...
Initially designed to alter "vanilla"(original,official) and forked projects, nowadays FCS should be able to install a new project from scratch.
Latest console clients can be dowloaded from here(md5:).

Flavours available: