Persistent Salgol is a dialect of S-algol that I developed for my PhD. The original version of S-algol was developed by Ron Morrison at St-Andrews University. My version here is written in Turbo Pascal and has the following features:
Borland style IDE
Fast 80x86 code generation
128 bit persistent virtual address space
Class hierarchy with inheritance mechanisms
It is available in source code form.
It is documented in my book A Compiler Writer's Toolbox, extracts from which are online as teaching notes.