Gecko
Gecko is a web rendering engine developed by Mozilla Foundation. This engine is known for being used to develop browsers, bots, applications and email clients. See below the software that is developed using the Gecko engine.
By the way, maybe you are looking for Gecko user agents?
Browsers:
- Alienforce
- AOL Shield
- Avant
- Blackhawk
- Camino
- Chimera
- Classilla
- CometBird
- Conkeror
- Cunaguaro
- Cyberfox
- Epiphany
- Fennec
- Firebird
- Firefox
- Flock
- Galeon
- Iceape
- IceCat
- Icedove
- IceDragon
- Iceweasel
- K-Meleon
- K-Ninja
- Kazehakase
- KMLite
- Light
- lolifox
- Lunascape
- MicroB
- Midori
- Minimo
- Mozilla
- MultiZilla
- My Internet Browser
- Navigator
- Netscape
- Nokia Proxy Browser
- Orca
- PaleMoon
- Phoenix
- Pirate Browser
- Prism
- QwantBrowser
- Sailfish Browser
- Saina
- SeaMonkey
- Sharp
- SlimerJS
- TenFourFox
- TinyBrowser
- Vonkeror
- Waterfox
- Wyzo
- YaaniBrowser
- Zvu