Openwengo is a community of Free Software enthusiasts. The OpenWengo community is sponsored by Wengo, a French SIP provider, itself backed by Neuf Cegetel, a French telco.
The first and major piece of software OpenWengo produced is known as WengoPhone Classic, a SIP compliant VoIP client. Several other Free Software projects are in concurrent development. Among them, WengoPhone NG (for Next Generation), will be a refactored version of WengoPhone Classic. In the past, WengoPhone NG has been referred to as "Picard".
Openwengo also recently published a WengoPhone Firefox extension, which allows you to make calls from the Mozilla Firefox web browser. Versions for Microsoft Windows, Mac OS X and Linux are available, although the latter is still in development.