Question

Are there any C/C++ libraries available that can be used in creating, loading and saving files in .odt-format?

Alternatively, where can I find tutorial-like information on implementing .odt(/ODF) specifications?

Answer 1

This site: OASIS OpenDocument Essentials seems to cover the problem, including howto-examples and shortcuts.
It’s quite nicely done and easy to follow.

Flexibility can be perceived as complexity. If you don’t need the
flexibility, create a template ODT and just fill in the content as
needed. As mentioned, there exist XML parsers to actually handle IO.
ODT isn’t a plaintext file, so some complexity/difficulty is expected.
– Ioan

From the link:

The Virtues of Cheating

As you begin to work with OpenDocument files, you may want to write a
program that constructs a document with some feature that isn’t
explained in this book—this is, after all, an “essentials” book. Just
start OpenOffice.org or KOffice, create a document that has the
feature you want, unpack the file, and look for the XML that
implements it. To get a better understanding of how things works,
change the XML, repack the document, and reload it. Once you know how
a feature works, don’t hesitate to copy and paste the XML from the
OpenDocument file into your program. In other words, cheat. It worked
for me when I was writing this book, and it can work for you too!