Infer is a static program analyzer for Java, C, and Objective-C, written in OCaml. Infer is deployed within Facebook and it is running continuously to verify select properties of every code modification for the main Facebook apps for Android and iOS, Facebook Messenger, Instagram, and other apps. It can be used for other code too: Infer can also analyze C code, and Java code that is not Android. At present Infer is tracking problems caused by null pointer dereferences and resource and memory leaks, which cause some of the more important problems on mobile.
Infer came to Facebook with the acquisition of the verification startup Monoidics in 2013. Monoidics was itself based on recent academic research, particularly on separation logic and bi-abduction.
We have broadened Infer's scope within the past few years. We now refer to the original separation logic analysis as Infer.SL. We now also have Infer.AI, a general analysis framework which is an interface to the modular analysis engine which can be used by other kinds of program analyses (technically, called ''abstract interpretations'', hence the AI monicker). This added generality has been used to develop instantiations of Infer.AI for security, concurrency and in other domains. Additionally, we have Infer linters for describing shallow syntactic analyses, using the AL language, because sometimes linters are just what you need.