| when did the source engine come out | 0.92 | 0.8 | 1790 | 35 | 10 |
| how old is the source engine | 1.26 | 0.5 | 7172 | 28 | 76 |
| source engine release date | 0.54 | 1 | 9784 | 26 | 10 |
| when did source come out | 0.14 | 0.7 | 7962 | 24 | 46 |
| who made source engine | 1.12 | 0.7 | 3946 | 22 | 20 |
| what is the source engine based on | 1.07 | 0.9 | 5924 | 34 | 89 |
| what is the source engine coded in | 1.52 | 0.7 | 2629 | 34 | 45 |
| when was source made | 0.87 | 0.5 | 40 | 20 | 18 |
| when was the engine made | 1.49 | 0.7 | 2845 | 24 | 15 |
| source engine source code | 0.93 | 0.6 | 8020 | 25 | 45 |
| what program is source engine made in | 0.81 | 0.9 | 3991 | 37 | 28 |
| source engine 2 release date | 1.48 | 0.3 | 6449 | 28 | 25 |
| source engine free download | 0.57 | 0.4 | 9065 | 27 | 97 |
| what language is source engine written in | 1.36 | 0.8 | 2796 | 41 | 57 |
| source engine pc download | 1.17 | 0.8 | 9155 | 25 | 22 |
