This is a Small Basic development environment (IDE) with debugger, flow chart visualisation, shapes and controls editor, extension management, extended editing as well as all of the features present in the standard Small Basic IDE.

It should work with any installed version of Small Basic (C:\Program Files (x86)\Microsoft\Small Basic or C:\Program Files\Microsoft\Small Basic).  The debugging functions do require Small Basic version 1.1 or later since it uses .Net 4.5 features present in this version onwards.

Thanks to gungan37 for some of the ideas.

Feedback welcome...

See the main Small Basic forum thread for SB-Prime for additional questions/requests/bugs etc.


  1. Download and save the zip somewhere
  2. Unblock the downloaded zip file (this allows the unzipped exe and dlls to be used): Locate the downloaded zip in File Explorer, then right click -> Properties -> General -> Unblock
  3. Unzip the contents of the zip somewhere, maybe an empty folder in Documents or in the SB installation folder (not the lib folder)
  4. Run SB-Prime.exe



A short guide to debugging with SB-Prime (How to Debug).


Plugins may be written for SB-Prime.  A sample VS 2017 project to get you started may be downloaded from

A GitHub version of the plugin sample source code is also available from

Plugin dlls should be unblocked if downloaded, then placed in a subfolder of the SB-Prime.exe location, called 'plugins'.

Using the plugin sample, only the SBSamplePlugin.dll file should be placed in the plugins folder.

The dlls in the plugins folder will be auto detected and loaded to a new ribbon button if they are are correctly created.


Updates (recent at top)

To update SB-Prime select the Advanced ribbon tab, and then click Update from the Settings group. Upgrade will persist your settings, otherwise you should download, unblock and install to the same location (overwrite) to maintain settings.