This version is compatible with MATLAB 7.8 (R2009a) through 8.2 (R2013b), and is freely available subject to a BSD(new) license. Past releases of the software (with support for MATLAB 7.4 (R2007a) and 7.7 (R2008b)) are available here.
Alternatively you can install Chebfun to your current directory by pasting the code below to your MATLAB command window:
We're eager to hear what you think about Chebfun. Contact us at firstname.lastname@example.org with questions, bugs, comments, suggestions, requests, compliments, or descriptions of interesting uses you have found for Chebfun. You can keep track of news about major releases, events, and other Chebfun-related activity by subscribing to the chebfun-announce and chebfun-discuss mailing lists, simply by sending a blank email to email@example.com or firstname.lastname@example.org.
Thank you for your interest in Chebfun! We look forward to staying in touch.
-- The Chebfun Team
Furthermore, if you're interested in closely following or contributing to the development of Chebfun, look at the developer zone or consider subscribing to the other mailing lists. In particular, for those wishing to try out the latest developments in Chebfun without checking out from the SVN repository, we offer access to the latest nightly build.
It should be noted that this is considered unstable, and most users should download the latest stable release above.