Persistent

Architecture of the PEVM: A High-Performance Orthogonally Persistent Java Virtual Machine
Describes design, implementation of new scalable, high performance implementation of orthogonal persistence for Java platform (OPJ). Based on Sun Microsystems Labs Virtual Machine for Research (ResearchVM); features: optimizing Just-In-Time compiler, exact generational garbage collection, fast thread synchronization.
http://www.sun.com/research/techrep/2000/abstract-93.html

Forest Project
Investigated using persistent object technology in building large-scale software development environments. In time, became more about developing persistent object technology; broadened scope to provide support for all Java applications that manage long-lived, large-scale, complex, shared data.
http://www.sun.com/research/forest/

A Persistent System in Real Use: Experiences of the First 13 Years
Eumel and successor L3, OSs made by GMD, have been used for 13 and 4 years respectively, for production in business, education. Over 2000 Eumel, 500 L3 have shipped since 1979, 1988. Both rely on persistence, with fault-surviving. Description, links. [ResearchIndex, CiteSeer]
http://citeseer.ist.psu.edu/liedtke93persistent.html