There are available engines and their known versions (This list may be extended at any time):

TheXTech:
- thextech      TheXTech + SMBX Assets
Allowed versions:
- 1.3.1
- 1.3.2.x
- 1.3.3.x
- 1.3.4.x
- 1.3.5.x
- 1.3.6.x
- 1.3.7.x
- 1.8.x


SMBX Original (SMBX 1.3 and below):
- smbx13        Super Mario Bros. X 1.3
- smbx120       Super Mario Bros. X 1.2.x
- smbx110       Super Mario Bros. X 1.1.x
- smbx100       Super Mario Bros. X 1.0.x


SMBX-38A:
- smbx38a       Super Mario Bros. X by 38A
Allowed versions:
- 1.4.0
- 1.4.1
- 1.4.2
- 1.4.3
- 1.4.4
- 1.4.5


LunaDLL:
- lunadll       LunaDll (pre-Lua)
Allowed versions:
- 7
- 8


LunaLua:
- lunalua       LunaLua-SMBX (SMBX 1.3 with Lua)
Allowed Versions:
- 0.7.x


SMBX2:
- x2            Super Mario Bros. X2
- x2b2          Super Mario Bros. X2 Open Beta 2
- x2b3          Super Mario Bros. X2 Beta 3
- x2maglx3      Super Mario Bros. X2 MAGLX3
- x2pal         Super Mario Bros. X2 PAL
- x2b4          Super Mario Bros. X2 Beta 4
- x2b5          Super Mario Bros. X2 Beta 5
Allowed versions:
- Beta 2
- Beta 3
- Beta 4
- Beta 4, Patch 1
- Beta 4, Patch 2
- Beta 4, Patch 3
- Beta 4, Patch 4
- Beta 4, Patch 4.1
- Beta 5
- Beta 5, Patch 1
- Beta 5, Patch 2
- Beta 5, Patch 3
- Beta 5, Patch 4
- ...