Inkscape - Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.
Paperless Post - Paperless Post is an online platform for creating custom card and invitations.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Manvite - As the name of this service suggests, the users can avail easily and simply invite rather than online summons that are blessed with flowery fonts and dabbling champagne glasses.
Sculptris - Sculptris: Enter a world of digital art without barriers.
Anyvite - Anyvite provides an efficient way to create invitations, with a range of tools necessary to organize and communicate with attendees throughout the event lifecycle