From the Preface to A.D. Falkoff and K.E. Iverson, APL\360 User's Manual, IBM, 1968-08. link (7.3M)
The APL language was first defined by K.E. Iverson in A Programming Language (Wiley, 1962) and has since been developed in collaboration with A.D. Falkoff. The APL\360 Terminal System was designed with the additional collaboration of L.M. Breed, who with R.D. Moore, also designed the S/360 implementation. The system was programmed for S/360 by Breed, Moore, and R.H. Lathwell, with continuing assistance from L.J. Woodrum, and contributions by C.H. Brenner, H.A. Driscoll, and S.E. Krueger. The present implementation also benefitted from experience with an earlier version, designed and programmed for the IBM 7090 by Breed and P.S. Abrams.
The development of the system also profited from ideas contributed by many users and colleagues, notably E.E. McDonnell, who suggested the notation for the signum and the circular functions.
In the preparation of the present manual, the authors are indebted to L.M. Breed for many discussions and suggestions; to R.H. Lathwell, E.E. McDonnell, and J.G. Arnold for critical reading of successive drafts; and to Mrs. G.K. Sedlmayer and Miss Valerie Gilbert for superior clerical assistance.
A special acknowledgement is due to John L. Lawrence, who provided important support and encouragement during the early development of APL implementation, and who pioneered the application of APL in computer-related instruction.
 I.P. Sharp Associates, Toronto, Canada.
 General Systems Architecture, IBM Corporation, Poughkeepsie, N.Y.
 Science Research Associates, Chicago, Illinois.
 Computer Science Department, Stanford University, Stanford, California.
 Industry Development, IBM Corporation, White Plains, NY.