With so many Mashups coming up daily and being largely motivated by the revenues attractive mashups make, I am sure that there are lots in the developer circuit who are waiting for a right API to build their Mashup on. To all such people out there, here is a wonderful URL, programmableweb, that has aggregated most popular APIs that are available online.
There are APIs defined by category, like Music, Office, Blogging, Payment, Photos, Travel, Utility and many more. Most APIs here are based on REST architecture( nearly 60%), followed by SOAP.
Want to know about the hard-hitting Mashups ? Programmableweb’s another feature is showcasing the popular Mashups, as you can see here. As of today, most Mashups are based on Mapping, Video, Travel and also microblogging.
For Flash enthusiasts, here are a set of APIs from Programmableweb.
So, get started and build your mashup today.