The LPROJ extension is used in folder names associated with Apple operating systems. Such folders often contain files with the STRINGS and NIB extensions. LPROJ are folders used by the Xcode integrated development environment. Each development project contains a Base.lproj folder containing files with the STORYBOARD or XIB extension. There are also folders for specific languages (for English en. Lproj , German de.lproj , etc.)

Xcode is a utility that Apple includes with Mac OS X.