Hi David,
SQL Anywhere is a product of SAP and PowerBuilder is a product of Appeon so you need to obtain SQL Anywhere separately from SAP if that is the database you want to use.
I believe you can obtain a free developer edition of SQL Anywhere from SAP, but the issue is that SQL Anywhere 11 was discontinued long ago so SAP not distributing such extremely old version anymore. You can download SQL Anywhere 17 here: https://www.sap.com/cmp/td/sap-sql-anywhere-developer-edition-free-trial.html
Starting from PowerBuilder 2021, we are updating the demo apps to support PostgreSQL in addition to SQL Anywhere so our customers have a free and open source DB option.
Best regards,
Armeen