User scripts are relatively short pieces of code that can be installed, enabled, and disabled by individual users in order to modify the behavior of the Tatoeba user interface. These scripts can serve an important role in streamlining tasks that you do frequently and adding functionality that has not yet been incorporated into the main codebase. Some scripts require editing for customization. They require an add-on to work with a browser.
On Google Chrome, Tampermonkey serves the same purpose.
See the Wikipedia page on Greasemonkey for add-ons for other browsers.
At the moment, the best way of finding a current, comprehensive list of Tatoeba-related scripts is to search the website userscripts.org for scripts tagged "Tatoeba". To see a discussion of individual scripts, see the next section.
Also see a4esl.com/temporary/tatoeba/userscripts/ (Someone should eventually add all of these to these page.)
Description of selected scripts
Tatoeba Default Languages (author: FlamingTofu) moves your desired languages to the top of the language drop-down lists. You need to edit the script once to list the languages you desire.
Tatoeba Search Language Switcher (author: Pandark) replaces the single-headed arrow between the two language fields at the top of the screen with a double-headed arrow. Clicking on the double-headed arrow swaps the values in the "From" and "To" fields. The script does not require any editing.
Tatoeba Sentence Timeline (author: jakov, known as jakovo at userscripts.org) places log entries and tags chronologically between the comments on a sentence. The script does not require any editing. WARNING: The current version of the script interferes with comments as they are now displayed.
Tatoeba Symbol Insert Helper (author: jakov/jakovo) adds links for inserting special characters into the Tatoeba translation boxes. It can optionally be edited in order to remove unwanted character sets from the list, add new ones to the list, or modify the order in which they appear.
htmlTatoebaQuiz (author: marcelostockle/Marcelo Stöckle) quizzes the user. It uses Tatoeba's "light" view (tatoeba.org/s/s/sentence_number).
Tatoeba Suggest Tags of Siblings (author: jakov/jakovo) lists the tags which have already been added to direct translations (in green, like: ) and indirect translations (in grey, like: !), so that you can easily pick one for the active sentence. When you hover on a tag added to the active sentence, it also makes it possible to see the name of the contributor who added it. For tags added to direct and indirect translations, hovering will highlight the related sentence. Similarly hovering on a sentence number in the logs will highlight the sentence with this ID. The script will add a control panel on your profile for determining preferences.
For the time being, place requests involving creation or modification of scripts on the page User script requests. Eventually, we can use a more sophisticated tracking system.