There are continuous creation of new tools in Digital Humanities, so the lists here are not exhaustive or definitive, neither are the categories.
A very useful source of tools is TAPoR which now includes the DiRT (Digital Research Tools) Directory. TAPoR provides reviews and recommendations of text manipulation, analysis and visualisation tools.
A companion website to TAPoR is Methodica Commons which provides research methods and techniques for analysing texts
Omeka is an open source platform commonly used by librarians, archivists, and museum professionals to create digital exhibits. There is a basic version of the software that can be hosted through the web and a more advanced version that requires web-hosting from an institution.
Murkutu is an ethically-minded, community-driven online archiving platform for cultural heritage material.