Built by developers Julian Shapiro and Thomas Davis, Libscore features a search engine tracking JavaScript libraries. "Every month, it crawls the top million sites on the Web according to alexa.com traffic rankings," Shapiro said in an interview. For each site crawled, a few queries are run in real time; these queries help determine which third-party JavaScript libraries are in use on that Web page.
"Once this whole scan runs -- and it takes approximately 38 hours -- we aggregate that data and publicize it for anyone to use freely on Libscore.com," said Shapiro. Libscore detects modules loaded via RequireJS, JQuery plug-ins, window variables from non-JQuery libraries, and external scripts, a Web page introducing the site notes.
For developers, Libscore provides a transparent view into usage of a library, whereas previously, developers looking to assess library usage have been limited to looking at star counts on GitHub. "Of course, that star count is very limited and indirect," said Shapiro. "It doesn't really tell you anything other than how many people decided to hit the star button." Libscore could serve to motivate developers by giving them tangible feedback on who is using their work, he said.
Positioned as offering "the current state of JavaScript," Libscore provides competitive analysis of library usage, such as comparing Angular and Backbone, said Shapiro, author of the Velocity.js JavaScript library. Developers can get real numbers and make judgments on which library to use for their own projects, he said.
Libscore was launched as an open source project in partnership with payments processor Stripe.com and cloud services provider DigitalOcean.