Abbreviation of grams per litre.
"The mechanic explained that adding a few drops of fuel additive could raise the ethanol content from 10 gpl to 15 gpl, which might improve engine performance in cold weather."
To release under the GPL.
"The developer decided to open-source her new library by releasing it under the GPL so others could freely modify and distribute the code."
Initialism of General Public License.
"This entry is marked as gpl to indicate that its etymological roots come from a Germanic parent language rather than Latin or Greek."
Initialism of Germanic parent language.