Bottom is described as 'Yet another cross-platform graphical process/system monitor' and is a Process Management Tool in the System & Hardware category. There are eight alternatives to Bottom for Linux, Mac, BSD and Windows. The best alternative is htop, which is both free and Open Source. Other great apps like Bottom are Glances (Free, Open Source), Bashtop (Free, Open Source), BPYTOP (Free, Open Source) and vtop (Free, Open Source).
Glances is a cross-platform monitoring tool which aims to present a large amount of monitoring information through a curses or Web based interface. The information dynamically adapts depending on the size of the user interface.
Easy to use, with a game inspired menu system. Fast and "mostly" responsive UI with UP, DOWN keys process selection. Function for showing detailed stats for selected process. Ability to filter processes. Easy switching between sorting options.