AviSynth is an application created to be used in order to post-process various videos that might have been already saved, but are not quite ready to be shared with the public. In order to create a good quality video using this app, users can benefit from the frameserver feature. This allows people to edit a video file instantly without the need of creating a temporary file. There is no user interface for the tool, as it relies on a series of scripts that can work in order to edit the video in advanced ways.

The tool is small in size but various scripts can be added to it in order to create more interesting effects on a certain video. Moreover, any user that downloaded this tool can create his own scripts. Even though this might seem difficult in the beginning, users that want to create a script can consult the documentation provided by the developers. There, people can find in-depth explanation of everything. This way, all of the features of the tool or of a certain script can be easily discovered and used in order to process a video.

Every project that someone creates is self-documenting and this happens because there are no complicated syntax elements in the scripts. Every script is built using human readable text and this way, it is really easy to build a file that can be used as an effect for the video. Every effect that has been created can be saved into a library and it can also receive a name for sorting matters. After the script has been created, various tweaking options can be added to it in order to make the effect more flexible. The tool is distributed for free and the community can provide a lot of useful elements for other users.