Jess 7.0b5 is (probably) the penultimate release before Jess 7.0. As such, this release is all about enhancements and fixes rather than new features. The list of "smoothed edges" is impressive -- see below. The most significant changes are increased robustness in the debugger, and the restoration of the Jess 6 semantics for "modify" with multiple slots.
From the change log:
Don't "wrap" external JessExceptions in another JessException. Fix a logical/slot-specific interaction (thanks Shan Ming Woo). QueryResult gives better error messages for undefined variable parameters or for calling getXXX() before next(). Pretty-print zero-length multislot patterns correctly (thanks Jonathan Sewall). (map) handles multi-argument functions (thanks Yuri Gribov.) (watch) accepts multiple arguments. Bug in handling multiple multifields in slot-specific templates fixed (thanks Howard Greenblatt). QueryResult has full Javadoc. Added "ppdefrule *". Static imports handle overloaded methods. Fixed incremental reset for accumulate (thanks Roger Studner). Defadvice for nested function calls (thanks Ivan Op de Beeck.) undeffacts function added. JessDE parses functions for rule salience values (Gribov). XMLPrinter handles "or" conditional element properly. Reparsing bug with "accumulate" in the JessDE fixed (thanks Jason Morris.) "modify" now once again modifies multiple slots simultaneously. "max" and "min" return their arguments using their original data types. Debugger now correctly steps though router I/O statements.