z/XDC (Extended Debugging Controller) is an interactive program development and debugging tool for use with both application programs and systems-level programs running within most of the numerous execution environments (task mode, SRB mode, PC, SVC, cross memory, etc.) supported by IBM's z/OS operating system.

z/XDC can dramatically ease the problems and lower the costs associated with the development and maintenance of both simple and complex, low-level programs. z/XDC helps our customers deliver superior program products with lower error-rates and quicker times-to-market.

z/XDC consists of the main product, base/XDC, and additional functionality provided through optional, separately licensed features:

  • auth/XDC for debugging authorized programs running in normal and specialized environments

  • asm/XDC for Assembler Language support

  • c/XDC for IBM XL C, C++ and Metal C Language support


Base/XDC is the core component of z/XDC and must be licensed. It consists of all the program development support that ColeSoft has spent over 40 years building.

With base/XDC, you can debug:

  • Problem state programs (see auth/XDC for Supervisor State support)
  • Task mode code
  • Programs running with any user level execution keys (key 8, key 9, etc.)
  • Normal environments
  • Multitasking code and single threaded programs
  • 24-bit, 31-bit, and 64-bit programs
  • CICS programs, DB2 programs, and IMS and IDMS programs
  • TSO and ISPF command processors
  • Batch programs and started tasks
  • Problem mode product exits and modifications
  • And much more

Base/XDC includes the following built-in elements:

  • cdf/XDC- Cross Domain Facility
  • tfs/XDC - Terminal Full Screen Mode
  • rexx/XDC - REXX Scripting Support

Read more about the full functionality of base/XDC on our z/XDC Functionality page.

Optional Add-Ons:

Users can add additional functionality to base/XDC with several optional add-on features. These features rely on base/XDC and cannot be licensed independently.

auth/XDC Feature (Optional)

auth/XDC is an optional feature that enables the ability to use z/XDC to debug programs running authorized and running in specialized environments.

With auth/XDC, you can debug:

  • APF authorized programs
  • Supervisor state routines
  • Programs running with execution keys 0 through 7
  • Programs running in cross memory environments
  • SVC routines
  • PC routines
  • SRB routines
  • Programs running under the protection of FRR routines
  • System exits and modifications

asm/XDC Feature (Optional)

asm/XDC is an optional feature that activates those z/XDC capabilities that are Assembler specific.

With asm/XDC, you can:

  • Load and view symbol maps from Assembler-created SYM data
  • Load and view source image maps from Assembler-created ADATA
  • Load and manipulate and view DSECT maps for control blocks and data areas

c/XDC Feature (Optional)

c/XDC is an optional feature that activates those z/XDC capabilities that are C, C++ and Metal C specific.

With c/XDC, you get:

  • Source Statement Debugging of IBM XL C, C++ and Metal C.
  • Execution in 24-, 31-, and 64-bit environments.
  • STEP command (STEP IN / OUT / OVER).
  • Variable, array, and structure displays with drill-down techniques.
  • Stack Frame displays, any and all.
  • Automatic detection of transitions from Assembler to C language (and back again) for seamless multi-language debugging.
  • Automatic mapping of C modules when detected.
  • C source statements with or without the underlying Assembler intermixed.