Module comparison wishlist #1
PID files. About a decade ago I wrote Proc::PID_File, including fork() handling, it does the job pretty well but I ended up abandoning it in favor of Proc::PID::File because I don't have time to maintain it and I hated the name. Turns out that there are several other modules pertaining to PID files like Piddy, Pid::File::Flock, IPC::PidStat, even Unix::PID (which is not recommended). The comparison article should discuss what issues surround managing PID files and also mention other means to detect program instances, like locking DATA filehandle (forgot which module does this).
INI files. Tried several INI modules in the past, not satisfied with any of them. Used Config::IniFiles in the end, but recently wrote another implementation (unfinished). A comparison article could be helpful.
Command-line-argument processing. Have always used Getopt::Long, heavily used App::Options a few years ago, now settling with my own module. Recently there have been some new development efforts like MooseX::GetOpt, Moo::Getopt, and App::Rad.