  ParaSail is a language specifically designed to simplify the construction of
programs that make full, safe use of parallel hardware even while manipulating
potentially irregular data structures. As parallel hardware has proliferated,
there has been an urgent need for languages that ease the writing of correct
parallel programs. ParaSail achieves these goals largely through simplification
of the language, rather than by adding numerous rules. In particular, ParaSail
eliminates global variables, parameter aliasing, and most significantly,
re-assignable pointers. ParaSail has adopted a pointer-free approach to
defining complex data structures. Rather than using pointers, ParaSail supports
flexible data structuring using expandable (and shrinkable) objects implemented
using region-based storage management, along with generalized indexing. By
eliminating global variables, parameter aliasing, and pointers, ParaSail
reduces the complexity for the programmer, while still allowing ParaSail to
provide flexible, pervasive, safe, parallel programming for irregular
computations. Perhaps the most interesting discovery in this language
development effort, based on over six years of use by the author and a group of
ParaSail users, has been that it is possible to simultaneously simplify the
language, support parallel programming with advanced data structures, and
maintain flexibility and efficiency.
