Assuming that by "languages like" you mean open-source languages, the answer in general is that they are funded by the people that contribute their own time to it, and by the organisations that contribute their members' time to it.
Using Python as an example, Google uses Python extensively, and regularly contributes back to the project (not just Guido's work, but many other employees as well). I believe they're also happy for employees to spend some time contributing in non-coding ways (e.g. taking part in python-dev discussion). There are many other companies for which this is also true, to a greater or lesser extent.
Python also has the Python Software Foundation (PSF), which is funded for the most part by sponsors (typically large companies like ActiveState, Google and O'Reilly - the web page has a current list). Although the PSF isn't responsible for the day-to-day work on Python, it does advance the language in various ways, particularly related to funding - for example funding conferences (where often a lot of development is done), occasionally funding work on a specific project, working with "Summer of Code" students, and so forth.
Throughout much of the life of Python, one or more core developers have been employed to specifically work on development of Python itself (either part time or full). For example, Guido developed Python while at CWI, CNRI, BeOpen.com, and most recently at Google.
Other implementations of Python (work on which feeds back into the core Python and CPython) are funded in similar ways. For example, until very recently Microsoft funded (completely) the development of IronPython, and the European Union funded (partially but significantly) the development of PyPy.