PECompact compresses Windows modules (EXE, DLL, SCR, etc..) substantially, while leaving them able to be run just as before. At runtime, compressed modules are rapidly decompressed in memory. Smaller (<50%) size usually means quicker load time. PECompact generally compresses files much smaller than if they had been compressed by modern data compression software such as RAR. This is accomplished by restructuring and pre-processing that make modules more compressible. Compression also adds a layer of security to modules that resists tampering and reverse engineering. PECompact supports multiple compression formats, including LZMA. A GUI and console mode application are both included.