Thanks Jesse for mentioning us (note: I work for Mashery).  I'll leave the rest of this thread alone, but to add specifically to the pieces about Mashery...<p>Mashery has really big clients and really small clients.  We built our solution on AWS very shortly after it launched and know "the cloud", really really well.  We have clients with APIs that exist on EC2 or in their own cage.  Some clients are beta programs, some crank hundreds of millions of calls through us.  Working with us isn't so much about size, but what value you'd get based on your need.<p>We don't just provide a Portal.  But yes, we do provide a full solution for managing API's: portal, developer management, limiting, caching, authentication, analytics.  Things we think are important for people managing API's, big or small, science project or commercial.<p>Integration with Mashery can also literally be typing in a URL - but usually you need more if you want to expose an API, especially if you want it to be commercial.<p>We have clients that run commercial API programs.  There aren't too many big examples out there where people are charging per call and needing a toll booth as it were.  The day will come though so I'd agree.