This is F# Interactive Plugin for Notepad++
1) First of all download latest version of the Notepad++ and install it
For today it is Notepad++ 5.9.8 (Jan 5 2012)
2) Download NPPFSIPlugin Version 0.1.1.
3) Extract dll from achieve and copy it to Notepad++\plugins\ folder.
On the Win7 64bit machine it is 'c:\Program Files (x86)\Notepad++\plugins\'. In the case when you install Notepad++ with default setings.
4) Open or re-open you Notepad++ application.
5) Go to Plugins\F# Interactive\Options menu item.
6) Specify Binary Path to fsi.exe file.
For example:
F# 2.0 - C:\Program Files (x86)\Microsoft F#\v4.0\fsi.exe
F# 3.0 - C:\Program Files (x86)\Microsoft SDKs\F#\3.0\Framework\v4.0\fsi.exe
Before use this paths check that you you have installed appropriate version of F# in that location.
7) Save you changes. Now it should work.
Alt+T to open F# interactive
Alt+Enter to to send selected text to F# Interactive