1. An enhanced unwind apparatus for exceptions encountered during program runtime, comprising: an unwind library comprising at least one unwind service; at least one indexed table for replacing bytes that are used for addresses and region lengths with a stream of bit fields where each instruction in an instruction stream has a corresponding entry in said at least one indexed table, wherein said unwind library computes a current regions' attributes using indexing provided by said at least one indexed table, and an unwind header table struct unwind header having a structure that includes one or more of the following descriptors: short num pages; short page size; short num svcs; int page tbl; int num regs; int reg tbl; int svc base; where: short num pages is a count of the pages in a page table; short page size is a count of instructions in each page of said page table; short num svcs is a count of the number of unwind services that are active in said program; int page tbl is an offset of said page table; int num regs is a count of the number of unwind regions in said program; int reg tbl is the offset of a region table; and int svc base is an array of offsets of each service table, where there is one service table per active unwind service.