.SLN File Extension

An SLN file is a structure file used for organizing projects in Microsoft Visual Studio. It contains text-based information about the project environment and project state.

When opened, the preSolution, Project, and postSolution information is read from the SLN file. This data is used to load the solution, projects within the solution, and any persisted information attached to the solution.

SLN files are similar to Windows Program Group (.VBG) files used by Visual Basic.