'10 Tacoma 4WD: What's inside my rear axle?

I was reading an online essay today about the Toyota Tacoma and it mentioned that my '10 Tacoma (reg cab 4cyl 4WD) does not have a rear axle limited-slip differential (LSD) but rather a 'system' that makes the axle act like it has one (VSC?). I have read posts on TW where owners have reported unusual activity (noises, etc) from their rear axles, presumably from the LSD. The essay I read indicated that the LSD was discontinued with either the '08 or '09 models. I thought that my '10 Tacoma came WITH a LSD; I was glad to see that since one of the first mods I did to my '95 reg cab 4cyl 4WD pre-Tacoma Toyota truck was to install a Detroit Tru-Trac in the rear axle (worked GREAT). If any knowledgeable users have more info on this I'd appreciate their input.