The architecture of the B5000 / B5500 / B6500 lives on today in the Unisys ClearPath line. I believe the OS, MCP, is one of the longest-maintained software operating systems still in active use, too.
One of the original brains behind the R1000 has mentioned that the B5500 was one of the inspirations, but my personal impression is that he was talking more about the stack-based (vs. register-based) instruction set, than the memory management.
There's some good background here for those who are interested: https://www.smecc.org/The%20Architecture%20%20of%20the%20Bur...
The architecture of the B5000 / B5500 / B6500 lives on today in the Unisys ClearPath line. I believe the OS, MCP, is one of the longest-maintained software operating systems still in active use, too.