.avsi file: how to open it on Windows

2 Windows apps register the .avsi extension. Install one of them to open the file with a double-click.

• 
  Notepad3

  Notepad like text editor based on the Scintilla source code.

  Free 7.26.602.1 84.4K ↓ ★ 6.7K
• 
  AviSynth+

  AviSynth+ is an improved version of the AviSynth frameserver, with improved features and developer friendliness.

  Open source 3.7.5.4289 8.6K ↓ ★ 1.2K

Related guide: Change the default app for a file type in Windows