Download of XSTABL 5.209 was on the developer's website when we last checked. We cannot confirm if there is a free download of this software available.
We cannot guarantee that the program is safe to download as it will be downloaded from the developer's website. Before launching the program, check it with any free antivirus software. The software lies within System Utilities, more precisely Automation. The actual developer of the software is Interactive Software Desigs, Inc.
From the developer:
XSTABL provides an integrated environment for performing slope stability analysis on an IBM personal computer, or compatible. The program combines an intuitive user friendly interface and the analytical philosophy behind the popular slope stability program, STABL, developed at Purdue University.
You may want to check out more software, such as LCDHype, VisualCron or Keybreeze, which might be similar to XSTABL.