The Development of PSL/Sugar http://www.doulos.com/knowhow/psl/development_pslsugar/ Sugar began as an internal development within IBM, where the CTL formalism (Computation Tree Logic) was used to express properties for model checking.
Usage of formal property specification languages is becoming widespread - 68% in 2007 (John Cooley, DVCon’07) - Properties often called “assertions” Properties are used not just in formal verification, but also in simulation - “Assertion-Based Verification” (ABV) Some property specification languages: PSL/Sugar, System Verilog Assertions (SVA), OVA, OVL, etc. All of these are just ways of writing variants of Temporal Logic