The purpose of Entweedle is simple - I've previously worked on projects where Twine 1.x was used as story planning tool, then an export of the underlying twee source was used in another environment. I noticed this feature had not made it into the official release of Twine 2, so I decided to learn Twine 2's story format to see if I could make twee source exports available.
Usage is also simple - add Entweedle as a story format, select it as the format of a story, and then play your story. The exported story will display only the plain text twee source of your story, which you can copy and paste elsewhere as needed. The generated twee source should generally comply with the Twee 3 format specification, but if you run into any incompatibilities or issues, please let me know.
To use Entweedle as a Twine 2 format, click the "Formats" link in Twine, then "Add a New Format" and enter this URL:
This will allow you to select Entweedle as a story format. Once selected, just Play your story, and copy/paste the generated twee source from the resulting export.
If you're using Entweedle for anything or you have any questions, comments, or issues, please drop me a line and let me know.