| source 1 release date | 2 | 0.3 | 5004 | 21 | 84 |
| source 2 release date | 0.73 | 0.3 | 2335 | 21 | 6 |
| what is source 1 | 0.93 | 0.7 | 7263 | 16 | 12 |
| when did source come out | 0.78 | 0.8 | 3552 | 24 | 51 |
| when does source 2 come out | 1.16 | 0.3 | 3675 | 27 | 88 |
| source engine release date | 0.84 | 0.9 | 3640 | 26 | 69 |
| when is source 2 coming out | 1.19 | 0.2 | 2136 | 27 | 42 |
| cs source release date | 1.87 | 0.8 | 4504 | 22 | 27 |
| source 2 engine release date | 0.26 | 0.6 | 7216 | 28 | 78 |
| source 1 to source 2 | 0.21 | 0.1 | 564 | 20 | 89 |
| source 1.1.1.1 | 1.68 | 0.9 | 6206 | 14 | 29 |
| source 1.6 | 1.07 | 0.4 | 5278 | 10 | 34 |
| source 1.5 | 0.85 | 0.7 | 7073 | 10 | 37 |
| source 1 real estate | 1.51 | 0.5 | 4519 | 20 | 58 |
| source one 7 hd | 1.02 | 0.5 | 7321 | 15 | 7 |
| when was source 2 made | 0.63 | 0.8 | 358 | 22 | 8 |
| when did cs source release | 0.84 | 0.3 | 1289 | 26 | 56 |
| source 1.8 /source | 0.81 | 0.9 | 1931 | 18 | 98 |
| when was source made | 1.5 | 0.2 | 6299 | 20 | 98 |
| when was cs source released | 0.62 | 0.3 | 9473 | 27 | 10 |
