libdb.so appears to be the Berkley DB library which provides embedded database support. I\\'m not sure why Apache requires this.
The latest RPM at rpmfind.net is:
db3-3.1.1704.6x.i386.rpm
BTW - Unless there is a specific reason you are trying to install an older (April 1999) version of Apache, I would recommend that you pick up the latest release (enhancements, bugfixes and security patches). The current RPM\\'ed version of Apache is apache-1.3.19-1.i386.rpm (March 2001).
Of course you should review what each of the above packages provide and require before you install. That information can be found at rpmfind.net
Good luck!