Definition: Rewrite each original sentence in order to make it easier to understand by non-native speakers of English. You can do so by replacing complex words with simpler synonyms (i.e. paraphrasing), deleting unimportant information (i.e. compression), and/or splitting a long complex sentence into several simpler ones. The final simplified sentences need to be grammatical, fluent, and retain the main ideas of their original counterparts without altering their meanings.
Input: Stallman pioneered the concept of copyleft and is the main author of several copyleft licenses including the GNU General Public License, the most widely used free software license.

Stallman started the concept of copyleft. He is the main author of several copyleft licenses. This includes the GNU General Public License. It is the most widely used free software license.