Ok, my company is looking at going with an accounting program called ACCPAC (www.accpac.com). It can run on quite a few different databases including: Pervasive.SQL, Microsoft SQL Server, IBM DB2, Oracle, and Ingres II. We want to run it on a linux server, so afaik Ms SQL is out? Anyway, I was wondering what all you though of ingres vs pervasive (or is there a better choice?).

Also, I would like to be able to interface out web-based applications with this in the future. Right now, everything is in PHP...so are any of these easier than others to use with php?

I posted this in the "other" forum (http://www.dbforums.com/t1051290.html), but I don't think it got read.

Having used Pervasive.SQL/Btrieve for 9 years, I obviously prefer it. I've not used Ingres since I was in college. I know that Accpac has been using Pervasive for a number of years so I would guess that it's probably pretty stable too. Pervasive offers an ODBC driver so you should be able to use it with PHP.
Good luck.