Hello,
I installed a fresh Drupal 5.1, enabled all modules and the latest development version from potx. Using potx, I extracted the pot files for a few core modules. I also extracted the po templates from http://drupal.org/project/drupal-pot in a separate directories. After comparing a few files from each directory, I've found that are differences between those two, although there shouldn't be any. For example:
$ msgcmp --use-untranslated aggregator-module.po aggregator-module-new.po aggregator-module-new.po:60: this message is used but not defined... aggregator-module.po:83: ...but this definition is similar aggregator-module-new.po:72: this message is used but not defined in aggregator-module.po aggregator-module-new.po:76: this message is used but not defined in aggregator-module.po aggregator-module-new.po:84: this message is used but not defined... aggregator-module.po:75: ...but this definition is similar aggregator-module-new.po:88: this message is used but not defined... aggregator-module.po:55: ...but this definition is similar aggregator-module-new.po:96: this message is used but not defined in aggregator-module.po aggregator-module-new.po:104: this message is used but not defined in aggregator-module.po aggregator-module-new.po:116: this message is used but not defined in aggregator-module.po aggregator-module-new.po:120: this message is used but not defined in aggregator-module.po aggregator-module-new.po:172: this message is used but not defined... aggregator-module.po:303: ...but this definition is similar aggregator-module-new.po:184: this message is used but not defined in aggregator-module.po aggregator-module-new.po:188: this message is used but not defined in aggregator-module.po aggregator-module-new.po:192: this message is used but not defined in aggregator-module.po aggregator-module-new.po:196: this message is used but not defined in aggregator-module.po aggregator-module-new.po:220: this message is used but not defined in aggregator-module.po aggregator-module-new.po:232: this message is used but not defined... aggregator-module.po:315: ...but this definition is similar aggregator-module-new.po:332: this message is used but not defined in aggregator-module.po aggregator-module-new.po:336: this message is used but not defined in aggregator-module.po aggregator-module-new.po:340: this message is used but not defined in aggregator-module.po aggregator-module-new.po:348: this message is used but not defined in aggregator-module.po aggregator-module-new.po:392: this message is used but not defined in aggregator-module.po msgcmp: found 21 fatal errors
aggregator-module.po is from drupal-pot and aggregator-module-new.po is the one extracted from potx. Obviously, there are a lot of extra messages in the potx generated file. I also noticed that there is an extra general.pot file from drupal-pot, which probably contains strings missing from the other modules of drupal-pot. drupal-pot also lacks color-module.pot.
What is the rationale behind this practice? What should I do if I wanted to translate the UI? Should I use drupal-pot or potx?