Semantic with other languages

[Andrea Crotti <andrea.crotti.0@gmail.com>]

I really would like to be able to jump very easily to the function
definition in
- my local files (local + same directory would be enough)
- eventually sources of the standard lib or in the path (in python or
  the C std library headers for example)

I tried to use ctags for some time but it's not so smart and it needs to
execute a command every time.

Now I've seen semantic and finally I'm using it very nicely for java and
C, but I'm not able to jump to some global stuff...
Any nice link to setup my environment?

Moreover I would like to add a new language (nesc) to semantic-able
languages, the language is just an extension of C, so I think I could
just take the same c module and extend it a little bit.

I tried to look in the code but it's quite hard to find where to go, any
hint to show me the way?
Thanks