Is there a GUI viewer of databases created by Database Events?
I ended up creating my own: https://github.com/dtrebbien/Songs-Database-Viewer

In my case, the database is a simple database of songs, where each record has "Artist Name" and "Song Title" fields, so my Songs Database Viewer just has two columns for those fields. Though, Songs Database Viewer is adaptable to other schemas by adding more table columns in Interface Builder and setting the identifiers of the table columns to the field names.

Alternatively, a Database Events database is based on SQLite3, so the DBEV file can be opened with the command line sqlite3 utility. On Lion, the two important tables are ZRECORD and ZFIELD. Each row in ZRECORD corresponds to a Database Events record and each row in ZFIELD corresponds to a Database Events field.