The official sources for hintview are now on github:

https://github.com/ruckertm/HINT/tree/main/hintview/

There is always an OS specific directory (/Linux) and the common /backend directory.

to compile with GTK and the existing Makefile you set the WITH_GTK environment variable. So e.g.

cd Linux
WITH_GTK=2 make

Then the file chooser dialog will be compiled by GTK. Without GTK there is no such dialog but only the input file on the command line.
The user interface of the Linux version is very minimalistic. On the one hand it is a good starting point for own developments, on the other hand it is not very easy to use.
The key and mouse functions are described in a man page hintview.1.

I distinguish between the version for the viewer and the version for the HINT file version. I have just changed the output of the version, so that both versions are output. It now looks like this

./hintview --version
hintview version 1.3.1
HINT file format version 2.0

drwxr-xr-x root/root         0 2023-07-20 16:39 ./
drwxr-xr-x root/root         0 2023-07-20 16:39 ./usr/
drwxr-xr-x root/root         0 2023-07-20 16:39 ./usr/bin/
-rwxr-xr-x root/root    554608 2023-07-20 16:39 ./usr/bin/hintview
drwxr-xr-x root/root         0 2023-07-20 16:39 ./usr/share/
drwxr-xr-x root/root         0 2023-07-20 16:39 ./usr/share/doc/
drwxr-xr-x root/root         0 2023-07-20 16:39 ./usr/share/doc/hintview/
-rw-r--r-- root/root       158 2023-07-20 16:39 ./usr/share/doc/hintview/changelog.Debian.gz
-rw-r--r-- root/root      1144 2023-07-20 16:39 ./usr/share/doc/hintview/copyright
drwxr-xr-x root/root         0 2023-07-20 16:39 ./usr/share/man/
drwxr-xr-x root/root         0 2023-07-20 16:39 ./usr/share/man/man1/
-rw-r--r-- root/root      2166 2023-07-20 16:39 ./usr/share/man/man1/hintview.1.gz

Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
Source: https://hint.userweb.mwn.de/
Upstream-Name: hintview
Upstream-Contact: Martin Ruckert <ruckert@cs.hm.edu>

Files:
 *
Copyright:
 2020 - 2023 Martin Ruckert <ruckert@cs.hm.edu>
License: GPL-2+

Files:
 debian/*
Copyright:
 2023 Hilmar Preusse <hille42@web.de>
License: GPL-2+

License: GPL-2+
 This package is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; either version 2 of the License, or
 (at your option) any later version.
 .
 This package is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.
 .
 You should have received a copy of the GNU General Public License
 along with this program. If not, see <https://www.gnu.org/licenses/>
Comment:
 On Debian systems, the complete text of the GNU General
 Public License version 2 can be found in "/usr/share/common-licenses/GPL-2".

drwxr-xr-x root/root         0 2023-07-20 16:39 ./
drwxr-xr-x root/root         0 2023-07-20 16:39 ./usr/
drwxr-xr-x root/root         0 2023-07-20 16:39 ./usr/lib/
drwxr-xr-x root/root         0 2023-07-20 16:39 ./usr/lib/debug/
drwxr-xr-x root/root         0 2023-07-20 16:39 ./usr/lib/debug/.build-id/
drwxr-xr-x root/root         0 2023-07-20 16:39 ./usr/lib/debug/.build-id/30/
-rw-r--r-- root/root    161920 2023-07-20 16:39 ./usr/lib/debug/.build-id/30/0107b2b45aecf3422c491de84d8277bbbb6798.debug
drwxr-xr-x root/root         0 2023-07-20 16:39 ./usr/share/
drwxr-xr-x root/root         0 2023-07-20 16:39 ./usr/share/doc/
lrwxrwxrwx root/root         0 2023-07-20 16:39 ./usr/share/doc/hintview-dbgsym -> hintview

WARNING: No copyright found, please check package manually.