I am by no stretch of the imagination a relational database “expert”, but I have worked with Informix, Sybase SQL Server, Oracle, Btreive, Sybase SQL Anywhere and MS Access, among others. In my experience, working with MySQL is no more difficult than is working with all of the above, save Access and SQL Anywhere in a stand-alone (non-server) configuration.

Marco said: “while replication is fairly simple to set up, higher-end setups like clustering and advanced performance tuning require expertise that is not easy to find”
–I should think any good DBA with any major RDBMS under their belt would have no trouble doing these things in MySQL.

Marco also said: “At the most basic level of database usage, another threat to MySQL is slowly becoming significant: the fact that a whole generation of developers who has learned to use nothing but relational structures for their data is suddenly discovering the fact that, really, they don’t actually need relational databases for most of their work and that, indeed, RDBMSs are making it more difficult to perform certain functions”
–HUH??? Isn’t the most basic level of (relational/MySQL) database usage using them in non-relational ways (IOW, as a flat-file type storage system)? If you don’t need a relational database for a certain function, don’t use one. Simple.

Tom said: “I believe most of the value of MySQL lies in the power of the name “MySQL” – not in the product.”
–I believe most of the value of MySQL lies in the fact that it is a defacto standard for (even many of the cheapest shared) web hosting platforms. It comes built-in and ready to use, and is often the ONLY RDBMS offered (ok, MS SQL Server is pretty common these days too). Add to that the fact that in recent years, important “new” features have been added to MySQL, bringing it _closer_ to the “enterprise RDBMS” ideal (much like Microsoft did with SQL Server).

1) MySQL is not intended to be used for clustering and high-end applications at all. While you _could_ use it for these things also, it is not and will never be the core of the audience.
I believe that MySQL is a beginner’s database best used for low-end apps, where MySQL is a low-budget, light-weight database for hosting providers (who might need some training and support but not too much).
One of MySQL’s benefits is, that it is light-weight enough that you may even put it on a CD-ROM and run it from there with about zero extra configuration.

2) I believe most of the value of MySQL lies in the power of the name “MySQL” – not in the product. Most people who would never use any other database than MySQL, don’t use any high-end features. So obviously any other database could also do the job – but “any other database” is not “MySQL”.
That’s why I strongly believe that forking MySQL is non-sense, since you can’t fork the name.

3) I do think that companies like Zend could be an interesting candidate. MySQL is a perfect match for Zend’s new application server. They need tight database integration to compete with IBM Websphere and others anyway. Plus MySQL is most popular with most PHP users. Database support integrated in Zend Server support, together with Zend certification programs could be an interesting option.