Algol 60 comparison with Simula 67

Simula 67 = Algol 60 with Classes.

Simula 67 is an Object Oriented extension of Algol 60. All algol60 programs must be compiled using Simula 67 compiler! In addition to OOP features Simula 67 has:

Here will be (in 2015) reference to simula67.org, where there will be much more information about Simula 67.