lp is a tool to list processes. It's similar to ps, but tuned for my
everyday needs:
lp tells me some things that I often care about which ps cannot tell me,
such as the number of open file descriptors for a process.
lp is not cluttered with things I rarely care about, such as the controlling
tty of a process.
lp is not encumbered with multiple flag regimes to maintain compatibility
with decades of slightly different Unix tools (see: ps -ef vs. ps aux).
More often than not, I use ps with grep, which has two annoying aspects:
The output elides the header row.
Unless you take care by writing something like grep [m]yprocess, the
output will usually include both the process(es) you care about and the
grep process.
lp fixes this pragmatically by providing a few flags to filter the process
list.