Thousands of Facebook applications and third-party sites that utilize the social network’s login capabilities experienced a two-hour outage last night.

An issue with Facebook’s central JavaScript files prevented apps and some aspects of Facebook-connected sites from loading. Although the bug was reported and resolved within two hours, developers might notice a temporary dip in their apps’ usage for Thursday.

A user filed a bug report about the JavaScript issue, noting that all Zynga games were down, at 7:41 p.m. Pacific Daylight Time. Facebook acknowledged the service disruption at 8:30 p.m. on its platform status page, and declared the issue resolved at 9:55 p.m.

The incident is a reminder for the many developers that depend on Facebook for login and other features how their businesses can be affected when the platform experiences outages. The social network’s vision is to have all websites and applications integrate its Open Graph, but the more companies do so, the more critical it becomes to keep the platform stable and prevent issues from affecting users and developers globally. These types of disruptions will come under additional scrutiny after Facebook becomes a publicly traded company, as it is expected to this summer.

Thanks to Louis Goddard for the tip.