The pager functions used by help() in StdLib's pydoc.py don't detect IronPython correctly and the result is a lack of functionality or in some cases a hang. This is similar to issue 8110 in that the code attempts to detect windows with a check for "win32" from sys.platform and needs to check for "cli" as well to detect IronPython running on mono on linux/mac os or on windows.

My naive change to workaround the problem was to add the two line test for "cli" amidst getpager() here:

    if sys.platform == 'win32' or sys.platform.startswith('os2'):
        return lambda text: tempfilepager(plain(text), 'more <')
    if sys.platform == 'cli':
        return plainpager # IronPython
    if hasattr(os, 'system') and os.system('(less) 2>/dev/null') == 0:
        return lambda text: pipepager(text, 'less')

That two line addition allowed basic function and prevents the hang though maybe there is a better pager type that would work on IronPython. In our linux and windows tests though neither the tempfilepager nor pipepager would function on either platform.

I submitted the report to the IronPython issues tracker and someone there suggested posting the patch here.

There's a two line patch inline in msg201750.  If it's acceptable I'll do a formal patch myself unless someone else wants to pick this up.