howdoi : Instant coding answers via the command line.
semgrep : semgrep is a tool for easily detecting and preventing bugs and anti-patterns in your codebase. It combines the convenience of grep with the correctnes...
Sourcegraph : Sourcegraph Server is a free, self-hosted code search server that integrates with your code host and supports multi-repository, regexp, and diff searc...
ack is a tool like grep, optimized for programmers
Designed for programmers with large heterogeneous trees of source code, ack is written purely in portable Perl 5 and takes advantage of the power of Perl's regular expressions.