The ImportError is nice, but for the records it should be documented: :) Index: INSTALL =================================================================== --- INSTALL (revision 11042) +++ INSTALL (working copy) @@ -1,6 +1,7 @@ Requirements Python 2.2 or later. + ZopeInterfaces (http://zope.org/Products/ZopeInterface) SSL/TLS: PyOpenSSL 0.5.1 or later (http://pyopenssl.sf.net) Serial: PySerial (http://pyserial.sf.net)