The Salsa Commons API is a REST and XML API that, as Salsa explains,
"At it's simplest, using the Salsa API may consist of just a form placed on an external website ... At it's most complex, you could use a Ruby library to authenticate, pull down information on recent supporters and events, validate that data, change it, and submit it back to the node, while generating and displaying counts of petition signers -- all through the API."
Salsa focuses on helping not-for-profit groups and political campaigns do four things: fundraise, advocate, communicate and organize.
By providing their website (whose domain handles the calls from the API), data management, communication abilities, Salsa manages mailing lists for organizations, sends out emails, and runs fundraising campaigns, integrating responses. Highly customizable, it allows plugins for 3rd party apps. Last year it helped organizations reach 30 million Americans, and processed $100 million in donations.
In its biggest project to date, it helped the Electronic Frontier Foundation (EFF) and the Entertainment Consumers Association (ECA) boost opposition to Stop Online Piracy Act (SOPA) and the Protect IP Act (PIPA). They had 396,000 distinct supporters take over 420,000 actions over a 24 hour period resulting in the tabling of the legislation.
As EFF web developer Micah Lee put it, "We got a lot of new subscribers and a lot of people that weren't aware of their digital civil liberties until this action with SOPA."
Founded by two progressives, April Pedersen, a nonprofit professional, and Chris Lundberg, a software developer, Salsa is headquartered in Washington, DC.