Hi !
OScam and CCcam or mgcamd+newcamd... are SoftCam (Software Control Access Module), you can use several card localy without need to buy and use a physical CAM. And some SoftCam have too an emulation part like CCcam or Mgcamd, but not Oscam.
So some dev have create oscam-emu or osemu to had emulation's possibility to oscam. Oscam must be compiled with Oscam-emu (patch file) to had emulation for this SoftCam and Osemu must be launch after OScam to had too the emulation party to Oscam, but without need to compil.
OscamYmod and Doscam are non official oscam's forks with an emulation party added.
So you can use Oscam alone to read/use locals or externals cards and Oscam patched with OScam-emu or OScam + OSemu (you must launch the two binaries) to had an emulation party to Oscam.
Or use OscamYmod or Doscam to have the SoftCam Oscam + the emuation part but there aren't official version.
I hope to be clear...