DDNSServ is a fully featured server suite that allows you to run your own DDNS (Dynamic DNS server). You will have the ability to set trial periods, and pricing for your users. You could offer the service free of charge or take advantage of the built in registration and payment processing features.

The DNS Library is a COM object that makes dynamic DNS updates to BIND, Microsoft and other RFC-2136-compatible DNS servers possible from any scripting languages in an easy way. The library supports the following record types: A, MX, SRV, NS, CNAME, PTR, TXT. The library implements 5 components: DnsLibrary.Server, DnsLibrary.Resolver, DnsLibrary.Authentication, DnsLibrary.ResourceRecord, DnsLibrary.ResourceRecordSet. Secure updates supported.

File renamer converting Macintosh filenames for Windows when stored on a Windows Server, removing illegal characters and adding filenames extensions using a translation table easily customized.
Also truncates filenames longer than 31 characters.
You can install MacNames as Windows NT/2000/XP Service and keep the list of renamed files in a log. MacNames helps Windows-Macintosh cross-platform integration.

A Windows app which automatically prepares Macintosh filenames for Windows removing illegal characters and adding extensions using a conversion table.
Optionally as a Windows service it regularly scans and replaces characters allowed by Macintosh but forbidden in windows file names. Stored on Mac volumes of NT/2000/XP servers, the truncate to 31 characters function allows to view these files from Macintosh more friendly than DOS shortnames.