• Perform runtime arguments checks if DEBUG is defined to provide great development experience.
• Portability in mind.
• Use standard functions if FT_ALLOW_MEMSET is defined for instance or a custom implementation if not.
• Data structures and routines for strings, arrays, linked lists.
• Restrict features accordingly with standard functions availability.

42 projects main rules:

• There's a very restricted set of standard functions we're allowed to use.
• Most global variables are forbidden unless you cannot do without it.
• Custom functions cannot take more than 4 parameters.
• A custom function is 25 lines max.
• A line is 80 columns max.
• Custom macros shall not have as a primary purpose to bypass the above rules.