Ahrefs - Ahrefs is a toolset for SEO and marketing. We have tools for backlink research, organic traffic research, keyword research, content marketing & more. Give Ahrefs a try!

strace - Trace system calls and signals. A diagnostic, debugging and instructional userspace utility.

Smaller - Make your websites load faster

ftrace - A function tracer for the Linux kernel.

SE Ranking - All-in-One cloud-based SEO software for agencies, marketing teams and webmasters

Valgrind - Valgrind is an instrumentation framework for building dynamic analysis tools.