Sysdig is open source, system-level exploration: capture system state and activity from a running Linux instance, then save, filter and analyze. Think of it as strace + tcpdump + lsof + awesome sauce.
With a little Lua cherry on top.

Software developers using Windows have a fantastic process explorer, made by Mark Russinovich. Linux lacks such a process explorer tool. This projects aims (in the end) to be an equivalent process explorer for Linux.

Goal is to have the same functionality of the Windows process explorer under linux, or less if linux limits us.