Complex sentence: Also Project Gutenberg has two options for master formats which can be submitted (from which all other files are generated), customized versions of the Text Encoding Initiative standard since 2005, and reStructuredText, since 2011.
Split into simpler sentences: Also Project Gutenberg has two options for master formats which can be submitted (from which all other files are generated). PGTEI, a customization of the Text Encoding Initiative standard, since 2005; and PG-RST, a customization of reStructuredText, since 2011.