Gecko versions and application versions

The following table shows the various versions of Gecko and what versions of common applications are based on them. Note that after Gecko 2.0, both Firefox and Thunderbird versions are from then on the same as the Gecko version number, at Gecko 5.0.

Gecko version	Applications based on it
Gecko 24	Firefox 24, Thunderbird 24, SeaMonkey 2.21
Gecko 23	Firefox 23, SeaMonkey 2.20
Gecko 22	Firefox 22, SeaMonkey 2.19
Gecko 21	Firefox 21, SeaMonkey 2.18
Gecko 20	Firefox 20, SeaMonkey 2.17
Gecko 19	Firefox 19, SeaMonkey 2.16
Gecko 18	Firefox 18, Firefox OS 1.0, SeaMonkey 2.15
Gecko 17	Firefox 17, Thunderbird 17, SeaMonkey 2.14
Gecko 16	Firefox 16, Thunderbird 16, SeaMonkey 2.13
Gecko 15	Firefox 15, Thunderbird 15, SeaMonkey 2.12
Gecko 14	Firefox 14, Thunderbird 14, SeaMonkey 2.11
Gecko 13	Firefox 13, Thunderbird 13, SeaMonkey 2.10
Gecko 12	Firefox 12, Thunderbird 12, SeaMonkey 2.9
Gecko 11	Firefox 11, Thunderbird 11, SeaMonkey 2.8
Gecko 10	Firefox 10, Thunderbird 10, SeaMonkey 2.7
Gecko 9	Firefox 9, Thunderbird 9, SeaMonkey 2.6
Gecko 8	Firefox 8, Thunderbird 8, SeaMonkey 2.5
Gecko 7	Firefox 7, Thunderbird 7, SeaMonkey 2.4
Gecko 6	Firefox 6, Thunderbird 6, SeaMonkey 2.3
Gecko 5	Firefox 5, Thunderbird 5, SeaMonkey 2.2
Gecko 2	Firefox 4, Thunderbird 3.3, SeaMonkey 2.1
Gecko 1.9.2	Firefox 3.6, Thunderbird 3.1
Gecko 1.9.1	Firefox 3.5, Thunderbird 3, SeaMonkey 2.0
Gecko 1.9	Firefox 3
Gecko 1.8.1	Firefox 2, Thunderbird 2, SeaMonkey 1.1
Gecko 1.8	Firefox 1.5, Thunderbird 1.5, SeaMonkey 1.0
Gecko 1.7	Firefox 1.0, Thunderbird 1.0, Nvu 1.0, Mozilla Suite 1.7
older versions of Gecko match the Mozilla Suite versions