This is compiled simulator like VCS and NCVerilog, but slower then VCS and NCVerilog.
Few more things about this simulator are direct C kernel interface, Covermeter code coverage embedded, better integration with VERA and other Synopsys tools. This simulator is faster when it comes to RTL simulation. VCS : This is worlds fastest simulator, this is also a compiled simulator like NCverilog.This simulator is good when it comes to gate level simulations. NCVerilog : This is the compiled simulator which works as fast as VCS, and still maintains the sign off capabilities of Verilog-XL.Verilog-XL : This is the most standard simulator in the market, as this is the sign off simulator.