strace - Trace system calls and signals. A diagnostic, debugging and instructional userspace utility.
htop - htop - an interactive process viewer for Unix. This is htop, an interactive process viewer for Unix systems. It is a text-mode application (for console or X terminals) and requires ncurses. Latest release: htop 2.
Process Explorer - The top window always shows a list of the currently active processes, including the names of their owning accounts, whereas the information displayed in the bottom window depends on the mode that Process Explorer is in: if it is in handle mode you'l…
ftrace - A function tracer for the Linux kernel.
Process Lasso - Process Lasso is NOT yet another task manager.
Sysdig - Sysdig is an open source, system-level exploration that capture system state and activity from a running Linux instance, then save, filter and analyze.