Metakit is a small, portable database library using a hybrid relational / hierarchical data model with a column-wise internal storage format. For C++, include a single header file and 125 kb DLL or statically link directly. Ideal for desktops, embedded systems, smartphones, and PDAs. Bindings for Python and Tcl. A very mature, stable code base.
The Tcl Web Application Framework helps simplify writing Web applications in the Tool Command Language (Tcl). It provides the features that form the basis for writing an application, such as sessions, users, privilege separation, and an abstract database interface. It is currently under development, but stable for production use.
steelpoll is a Web polling application which allows you to quickly and easily create and manage polls by just editing plain Tcl files. A single poll can be created by editing the variables in a single file. You can optionally control votes by checking the user's IP address. A parsed vote log can be viewed. It doesn't require any SQL database backend because it stores the results in easily parsed plain text files. It doesn't use graphics to display poll results, which is great for text-based Web browsers.