2.2.1 The OS/390 Operating Environment
This section introduces the OS/390 operating environment. A publication entitled
OS/390 Introduction and Release Guide
, GC28-1725 is recommended for a better
understanding of OS/390. This book describes the information associated with
OS/390 including OS/390 books and books for participating elements.

2.2.1.1 OS/390 Product Content

The operating system environment that is called OS/390 consists of MVS/ESA SP
and its component products and functions.

Base Elements

As an example, OS/390 Version 2 Release 5 contains the base elements listed
below. Subsequent releases of OS/390 will contain similar components, their
replacements.

System Services

MVS/ESA SP
Base Control Program (BCP)
DFSMSdfp
EREP
ESCON Director Support
IBM High Level Assembler for MVS
ICKDSF
ISPF
JES2
MICR/OCR Support
MVS/Bulk Data Transfer (BDT Base)
TSO/E
3270 PC File Transfer Program
FFST
TIOC

Systems Management

HCD
ICSF
SMP/E
SystemView for MVS Base

Application Enablement

Language Environment
DCE Application Support
Encina Toolkit Executive
GDDM/MVS (includes PCLK and OS/2 Link)
OS/390 Application Enabling Technology
SOMobjects Runtime Library
VisualLift for OS/390 Runtime Library
C/C++ IBM Open Class Library
Chapter 2. Sizing the Effort 19