Vanitygen

Vanitygen can generate regular bitcoin addresses, namecoin addresses, and testnet addresses.

Vanitygen can search for exact prefixes or regular expression matches. When searching for exact prefixes, vanitygen will ensure that the prefix is possible, will provide a difficulty estimate, and will run about 30% faster. Exact prefixes are case-sensitive by default, but may be searched case-insensitively using the "-i" option. Regular expression patterns follow the Perl-compatible regular expression language.

Vanitygen can accept a list of patterns to search for, either on the command line, or from a file or stdin using the "-f" option. File sources should have one pattern per line. When searching for N exact prefixes, performance of O(logN) can be expected, and extremely long lists of prefixes will have little effect on search rate. Searching for N regular expressions will have varied performance depending on the complexity of the expressions, but O(N) performance can be expected.