View source for Hashcat

Hashcat is an open source password recovery tool for for Linux, OS X, and Windows.  With the release of hashcat v3.00, the GPU and CPU tools were merged into a single tool called hashcat. The CPU-only version became hashcat-legacy. Both CPU and GPU now require OpenCL. Many of the algorithms supported by hashcat-legacy (such as MD5, SHA1, and others) can be cracked in a shorter time with the GPU-based hashcat. However, not all algorithms can be accelerated by GPUs. Bcrypt is an example of this. Due to factors such as data-dependent branching, serialization, and memory (and more), oclHashcat/cudaHashcat weren't catchall replacements for hashcat-legacy.

hashcat-legacy is available for Linux, OSX and Windows. hashcat is available for macOS, Windows, and Linux with GPU, CPU and generic OpenCL support which allows for FPGAs and other accelerator cards. 

Password representations are primarily associated with hash keys, such as MD5, SHA, WHIRLPOOL, RipeMD, NTMLv1, NTMLv2 to name a few examples.   Hashcat uses precomputed dictionaries, rainbow tables and even brute-force approaches to find an effective and efficient way to crack passwords.