The TASKLIB data set concatenation defines the run-time libraries for the Assembler compiler and their order. Any number of run-time libraries may be specified. A TASKLIB definition is used by the Enterprise Extensions Dependency Build to create the proper search order for the required compiler module.
A program can allocate one or more data sets to a TASKLIB concatenation. Data sets concatenated to TASKLIB are searched after JPA, but before any specified STEPLIB or JOBLIB. For more information about TASKLIB, see MVS Programming: Assembler Services Guide.

The following is a list of common Assembler libraries that may be considered for the TASKLIB concatenation:
| Assembler | |
| Library: | Description: |
| SYS1.SASMMOD1 | The High Level Assembler load library. |