All forms of collaboration require some sort of centralized collaboration tool.
In Drupal this can be implemented with "Multi-Sites", "Organic Groups (OG)", and "Domain Access". These solutions all have their strengths and weaknesses.
The main issue however is when to choose "Multi-Sites", "Organic Groups (OG)", or "Domain Access".
First a short overview of the relevant points:
"Multi-Sites"
When you need to add your own php functions to drupal, you can simply embed them in the content, but that is not the best way.
The best way to add your own PHP functions to Drupal, would be to create your own function library module.
Lets hypothetically call your PHP function library "myfunctionlib", you will need to change that everywhere to reflect your own naming convention.
To create the PHP function library module first create a folder "myfunctionlib".
In that folder create a file called myfunctionlib.module with the following content:
In the same folder create another file called "myfunctionlib.info" with the following content:
The easiest and simplest way to embed video in a drupal post is by just copying and pasting the embed video code into the content you are making.
As with all things drupal, there's also at least one module for this;
To install modules in order to customize your Drupal install:
Just updated BobbyMods to 6.12.
I also updated a couple of multi-site installations, and if you didn't hack core and put the themes and modules where they should go (as opposed to where-ever it works) it should be fairly easy.
Here you can find all Drupal 6.x core upgrade projects that are not a part of another project.
These are all projects from people that just need an drupal core update done for them.
To request an upgrade from your current drupal version to the latest secure drupal version contact me and include your current drupal version and a list of used contributed modules (if known).