This folder is a place for temporary files generated by ttx # About TTX Installation The numpy module is required -- use "easy_install numpy" to install it. Download and extract fonttools from http://sourceforge.net/projects/fonttools/ in any folder on your computer. From the font tools directory run "python setup.py install" from the command line. # TTX for Mac Change On Mac OSX, if you are getting error message related to "/Library/Python/2.7/site-packages/FontTools/fontTools/ttLib/macUtils.py", line 18, in MyOpenResFile, use the following patch to change the fonttools https://github.com/mcolyer/fonttools/commit/e732bd3ba63c51df9aed903eb2147fa1af1bfdc2 # TTX for Windows Change On Windows, if ttx generate an exception, it waits for a key to be pressed. Pleaase change "/c/mozilla-build/python/Lib/site-packages/Font-Tools/fontTools/ttx.py" file: replace the waitForKeyPress function body with just 'return'.