INFORMIX-ESQL/C, 1989, Version 2.10.06C, for IBM PC AT, XT
Manuals and suite of ten 5.25" diskettes - unused, never installed.
Informix ESQL/C is an SQL application programming interface (API) that enables you to embed Structured Query Language (SQL) statements directly into a C program.
This is the original program, before the company was acquired by IBM.