The overall design considerations included a desire to ensure that multiple programming languages could be used cross-platform to access LedgerSMB logic and that security would be consistently enforced across these applications. Thus the LedgerSMB team envisioned a "one database, many applications" environment typical of SQL. The overall approach heavily leverages PostgreSQL roles (application users are database users, and are assigned roles). Access to the database logic for new code (added in 1.3 or later) goes through stored procedures which act like named queries. Permissions are sometimes granted on underlying relations or on the stored procedures. The stored procedures have semantic argument names, allowing for automatic mapping in of object properties. These are then exposed to the Perl code through fairly light-weight wrappers. User interface code wrapped around Template Toolkit, which is also used for generating PDF's via LaTeX, CSV files, Excel, Open Document etc. Workflow is handled through relatively light-weight Perl scripting.