The code to make the command-line epubcheck tool available through a web interface similar to this has also been released by the IDPF, however it does require a bit of development knowledge to compile, install and host1.
Should you wish to perform validation of many or large EPUB files, we suggest you either consider installing epubcheck yourself, or contact us in a commercial capacity to assist with installing it on your server.
We can't provide any technical support regarding this service, and any issues found with the validation functionality should be directed to the epubcheck project.
More information about meBooks, and our services regarding large-scale digitisation and eBook production can be found on our website.
If you've found this epubcheck service useful, you might be interested in our open-source web-based EPUB reading solutions.
Read your EPUB files in our browser-based reading system. Visit Readk.it Reader page and drag and drop your EPUB file into the browser window to start reading it.
Produce a single HTML file that contains all of the content for an EPUB — including images, video, what have you — along with the Readk.it reading system. This file can be distributed to users via email, and then read offline by double-clicking to open in their default browser. Examples of Readk.it Solo can be downloaded here.
1. We do provide some notes regarding compilation of this software (so, for instance, you can build and host it on your own server).