Designing a software laboratory

The purpose of this paper is to describe same methodological aspects of the design of the Pisa Software Laboratory-PSL- which is being implemented in Assembler 360, on a virtual machine generated by CP-67 on an IBM 360/67 computer. The PSL provides a special enviroment within which researchers, designers and students may experiment in building new software systems. The PSL is designed following the nucleus extension approach, as an opened system.