LibWapcaplet is a string internment library, written in C. It provides reference counted string interment and rapid string comparison functionality. It was developed as part of the NetSurf project and is available for use by other software under the MIT licence. For further details, see the readme.
You can browse the source code via the online interface. Alternatively, you can check it out with Git:
$ git clone git://git.netsurf-browser.org/libwapcaplet.git
LibWapcaplet is licensed under the MIT Licence.
If you would like to help develop LibWapcaplet, or have questions about the library, please join the NetSurf developer mailing list.