CRP Keeps Your Important Apps Running [Featured Windows Download]

Windows only: Free application CRP (Control Running Programs) performs
two related but separate functions: First, it keeps important
applications running no matter what, so if a program unexpectedly shuts
down, CRP fires it back up. Second, it sets a user-defined limit on the
number of running instances of an application. If you've ever
unknowingly shut down your IM application, for example, but you need to
always be available for your job, the automatic relaunching of
specified apps can come in really handy. The second bit of
functionality—limiting instances of an application—can be
useful when you launch an application intending to restore the
currently running instance but you get another instance instead. CRP is
freeware, Windows only, requires .NET 2.0.

CRP [via FreewareGenius]