Just a review of the tools availables online, and open source.

The last 2 are web based and very much focused on the kind of solutions I am looking for, so it’s pretty great.

If you are looking for a simple desktop tool, then the first 3 are more oriented toward this.

Nisk

Subtitle Edit is an open source subtitle editor

It is for desktop. In C#

Subtitld

Subtitld is an open source software to edit, transcribe and create subtitles. It is able to read and write various formats like SRT, SSA, TTML, SBV, DFXP, VTT, XML, SCC and SAMI.

Also desktop.

Gaupol

Subplayer

Web based. Really awesome. Made for translation.

Video Processing

Web Based. Django App. Dubbing based on video chunks