I looked in to Clarion about a year or two ago for a similar situation (Uptrends), but we decided not to pursue it. Clarion is still available and in development, and it doesn't look too bad to work with. According to Wikipedia, they are currently working on generating .NET code, so that may be the best bet for porting it: http://en.wikipedia.org/wiki/Clarion_programming_language

There's also an ODBC driver, but it's not free: http://www.softvelocity.com/products/database_tsodbc.htm

>Someone asked me today if I know anything about Clarion. They have an old program (maybe 10 yrs) with source, and are thinking of porting it so it can be used again today.