The C2 language is still under development. However, since it is an evolution of C, no major changes are expected. Still, some new features might break current code.

Component	Status	Notes
Parser	100%	pretty much parses everything. Could do a bit better for syntax errors
Analyser	100%	fully working
Plugins	100%	c2c supports plugins (refs, deps, unit_test, load_file, shell_cmd, etc)
C generator	99%	some corner cases still need to be implemented
IR generator	5%	basically only Hello World works (functions, strings, function calls)
Templates	10 %	Function templates work, but Struct templates (with functions) are not in yet.
Macros	0 %	Still in the design phase, maybe not needed?
Embedded	10 %	This means generating images for embedded targets, .S files, linker scripts, etc
QBE backend	5 %	Hello world works currently, but not much more
C2Format	0 %	A 'style' tool (like astyle, clang-format)

So the short status would be that for playing around with the language using the C-generating back-end, it's very usable for real projects