.IN File Extension

Generic file used by some spyware programs to track activity on a computer; should be checked with an anti-spyware program if the source of file cannot be verified.

Some examples of spyware files with a ".in" extension include "config.h.in," "configureconfigure.in," "makefile.in," and "net.h.in."

File used by the Consolidated Model of Fire and Smoke Transport (CFAST), a program used to model fire and smoke impact on buildings; contains input data, like room specifications, accessed by the program to model fire and smoke effects.

NOTE: IN files are generic, they can be used by other programs for data input.