Lighttpd

If it will work I'd like to use Lighttpd rather than Apache.

Would that be possible?

Yes, it is possible. As you noted, you have to convert the Nginx rewrite rules in https://11.chamilo.org/documentation/installation_guide.html#16._Rewrite to lighttpd rewrite rules. It is a fairly straightforward exercise.

Like nginx, lighttpd does not support the (awful and inefficient) .htaccess historical mess in Apache (which dates back decades ago to when machines had much, much, much less memory and CPU, and so you wanted a single web server with a small number of processes to handle HTTP requests for many different users on the same system). If you understand .htaccess syntax, you might review the .htaccess files to implement the access deny rules from the .htaccess, too. I did not see that implemented in the sample nginx config.

At the bottom of the lined page they show two ways to handle redirects - is any of that necessary with Lighttpd?

Yes, all of that is necessary to configure Chamilo as Chamilo documents that Chamilo needs to be configured.

FYI: lighttpd supports X-Sendfile, though it is not enabled by default. You must enable "x-sendfile" in the lighttpd config. Similar to nginx, I would recommend using lighttpd mod_fastcgi to run Chamilo. See "x-sendfile" and "x-sendfile-docroot" in mod_fastcgi.

Pre-emptively: if your next question is anything along the lines of "will you do it for me?", the answer is "No." Please make an attempt to do it yourself, and test what you do. Feel free to ask specific questions about what you have tried after describing how it does or does not work for you.

Thanks. I always prefer to do things myself - so that I may learn - and take good notes.

Am I correct in this ...

1. I need just go ahead and install Lighttpd, MariaDB 5+, and PHP 7.4 in OpenBSD?

2. Then make the 'rewrite rules' changes to Lighttpd?

3. Then install Chamilo?

yes

Are Steps 1 & 2 here still good to follow for OpenBSD?

https://docs.vultr.com/how-to-build-an-openbsd-php-postgresql-lighttpd-development-stack

Then, substitute MariaDB for PostgreSql at Step 3?

lighttpd is available as a package for OpenBSD and works well. lighttpd is tested on OpenBSD as part of our CI.

lighttpd is a web server and can work in front of Chamilo-LMS.

This is a forum for lighttpd, not Chamilo-LMS.

I am unable to answer your questions about "Will Chamilo-LMS work with ...?" I am sorry but the answer to all of your other questions is: "Why don't you try it?" or ask in Chamilo-LMS forums.

Thanks. I always prefer to do things myself - so that I may learn - and take good notes.

Please demonstrate this to yourself. Your current questions (for reassurance?) have occurred too quickly for you to have tried anything yourself.

My experience has been that when I don't ask these kinds of questions I waste many long hours chasing my tail.

Then, when I give up and ask - someone always says "Had you asked, someone would have told you that wouldn't work, you should have done ..."

Sigh.

I'll go, once again, into the valley ... and report back ...

PHP 8.3.10 installed.

Hit a wall with openbsd lighttpd - it's asking a question for which I've been unable to find an answer (not even a mention anywhere online) ...

Which do I want to choose to run lighttpd with MariaDB - or does it not matter?

Ambiguous: choose package for lighttpd
0: <None>
1: lighttpd-1.4.74
2. lighttpd-1.4.74-ldap
3. lighttpd-1.4.74-ldap-mysql
4. lighttpd-1.4.74-ldap-pgsql
5. lighttpd-1.4.74-mysql
6. lighttpd-1.4.74-pgsql
Your choice:

Which do I want to choose to run lighttpd with MariaDB - or does it not matter?

As with many things, what happens if you install a package and you find out that it is not what you need? Do you uninstall it and then install another package to try? Is it that onerous a task? Do you consider this step such a deep valley of effort?

lighttpd is a modular web server.
mod_auth describes the lighttpd mod_auth module and submodules.
mod_vhostdb describes the lighttpd mod_vhostdb module and submodules.

Chamilo-LMS is a PHP application which is independent from lighttpd and Chamilo-LMS use of a database is independent from any database use by lighttpd modules.

You should install the lighttpd base package and if you need optional lighttpd modules from supplemental packages, then install the additional lighttpd modules that you need.

There are many, many, many different operating systems and distributions. I do not know them all. OpenBSD packaging of lighttpd is done by OpenBSD package maintainers, not by lighttpd developers. If you have questions about specific contents of OpenBSD packages, please see the package descriptions for those packages. If those package descriptions are not clear, then please contact the package maintainer listed in the package metadata. tl;dr: I do not know everything. If you're using OpenBSD, then I presume you are intelligent enough to distiguish an OpenBSD packaging question from a lighttpd question.

Then, when I give up and ask - someone always says "Had you asked, someone would have told you that wouldn't work, you should have done ..."

You seem to be having some trouble with the nuance of how to ask good questions.
A general guide to asking technical questions well can be found at http://catb.org/~esr/faqs/smart-questions.html (external link)

Try something, rather than nothing, before asking questions. However, also avoid the other extreme of spending weeks before asking for help. There is a lot of space in the middle.

You're "giving up" and asking questions too quickly. I won't be responding again today.