Goanna is a fork of Gecko developed by Moonchild Productions.
Servo is an experimental web browser layout engine being developed cooperatively by Mozilla and Samsung. In 2020 the engine's development was transferred to the Linux Foundation.
Presto was developed by Opera Software for use in Opera. Development stopped as Opera transitioned to Blink.
Other software publishers have built browsers and other products around Microsoft's Trident engine. The following browsers are all based on that rendering engine:
Comodo IceDragon (Firefox-based web browser for Windows with privacy and performance enhancements, developed by Xcitium formerly Comodo Security Solutions)
Mosaic was the first widely used web browser. The National Center for Supercomputing Applications (NCSA) licensed the technology and many companies built their own web browser on Mosaic. The best known are the first versions of Internet Explorer and Netscape.