PELock vs UPX

PELock protects compiled 32-bit Windows applications against cracking, tampering, and reverse engineering, while providing software licensing tools. It protects Portable Executable formats including EXE, SCR, DLL, OCX, CPL, BPL, DPL, ACM, and AX. Anti-debugging methods detect cracking tools and block their actions. The license key manager handles users and keys, generates and verifies RSA-2048 keys, and can block illegally shared keys. Trials can be limited by days, executions, an expiration date, or minutes of use. A virtual DLL binder combines an application and libraries into one EXE, loading those libraries in memory without writing them to disk. SDK examples cover C/C++, Delphi, Lazarus, FreePascal, PureBasic, PowerBASIC, D, and Assembler. Plugins can add compression, detection, licensing checks, and loader functions. The maker lists Windows support from Windows 95 through Windows 10 and Server 2003 through 2012, with 32- and 64-bit support. Pricing starts at 59 one-time; listed licenses cost 159.00 USD or $299, paid once.

UPX is a portable executable packer and file compressor for Windows, macOS, and Linux. It works with executable formats including Windows programs and DLLs, macOS apps, and Linux executables; listed formats also include PE, ELF, Mach-O, COFF, DOS, and Atari/TOS. The project says compression commonly reduces program and DLL sizes by around 50%–70%. For most supported formats, compressed programs are self-contained and run as before without runtime or memory penalties. UPX can list, test, and unpack executables, and maintains checksums for compressed and uncompressed files. It is free software under GPL v2 or later, with a special exception allowing unmodified UPX to compress commercial programs. UPX does not add protection or encryption, and the project advises handling only trusted files. Linux users should account for documented tradeoffs: compressed executables may require more RAM or swap when multiple processes run, and the generic Linux format recreates the original file in /tmp before launch.