I am attempting to pip install the fintech library (I get the same error with easy_install) but it is returning "Sorry, platform or Python version not supported." I am running 3.5.2 in venv in OSX (I get the same error with 2.7 as well as in Windows). The latest version of the package was upgraded to support 3.5. Any idea what I am doing wrong? EDIT: Python is 64bit and here is the full message. EDIT 2: Looking into it - it seems this is the core of the issue. It attempts to download the package by generating a URL with this code: extension = Extension(nativestring('fintech'), [nativestring( 'http://www.joonis.de/pyfintech/v%s/fintech-%s-py%s-ucs%i-%s-%sbit.zip' % ( PKG_VERSION, PKG_VERSION, '%i.%i' % sys.version_info[:2], sys.maxunicode == 0xffff and 2 or 4, # UCS-2 or UCS-4 platform.system().lower(), struct.calcsize(b'P') * 8, # Py2.6 requires a byte string ))], language='download') The URL that is generated by my system is: http://www.joonis.de/pyfintech/v4.3.0/fintech-4.3.0-py3.5-ucs4-darwin-64bit.zip which does return 404 from the server. EDIT3: It appears that it is the -darwin- that is causing the issue. Both -windows- and -linux- generate good URLs. I will see what the URL generated on my windows machine is later on today. EDIT4: My Windows python version was 32bit which is what was causing the issue there. So from what I can tell you need 64bit python running on linux or windows to use this package. Continue reading...