>What would be the best way to make a software multi-companies. I use Stonefield Database Toolkit. Would SDT make things easier?

I've done it two ways. One was to have all the tables in one place, and each record in each table would have a company id - we did that for our accountants, who had other customers, but occasionally wanted to run a few things for a few companies together (because they belonged to the same group). There are a few tables, though, so inserting an extra field in each query didn't make it much harder.

In other cases, each set of data was in a separate data directory, and there was some centralized code to tell the app to close everything and go for a different directory. This was the easier way for richer apps, but then running any multiple customers query was more complicated.