These instructions apply to Manifold 8.0.29 and IronPython 2.7.5, superceding earlier instructions on the forum.
Get the current IronPython installer (not binaries) from here:
Run IronPython-2.7.5.msi. Confirm the default options, and confirm allowing it to make changes when it asks.
Create a new script, specifying IronPython as the language.
Uncheck the option to add references for standard .NET modules.
Open the script, then the Script > Reference dialog. There should be no modules listed.
Click the button to add a new reference. Navigate to IronPython.dll:
By default IronPython.dll is installed to \Program Files (x86)\IronPython for 64-bit Windows, or to C:\Program Files\IronPython for 32-bit Windows. If file extensions are hidden you may need to enable them in Windows Explorer options.
Run the script. You should get the Hello World message. (If not, re-read the above.)
Now the IronPython dlls have been automatically added to the .NET GAC (global assembly cache).
(You can see the compiled assemblies in \Windows\Microsoft.NET\assembly\GAC_MSIL\IronPython and \Windows\Microsoft.NET\assembly\GAC_MSIL\IronPython.Modules.)
In future, new IronPython scripts do not need an explicit reference to IronPython.dll. Manifold will find the assemblies in the GAC.
For each new IronPython script, set the language to IronPython, and always uncheck the option to add references for standard .NET modules. (You can add any necessary references inside the script itself.)
You can add an explicit reference to IronPython.dll for new scripts, but don't need to.