Just before v0.08 we added a very nice clean summary of recent changes to projects. Because this feature is pretty complex and spread over a lot of source code files, this a overall description of what is going on.
home() in home.inc.php
In the dashboard part of home() we get a list of recently changed projects and their latest changed tasks. The complex part here is distributing the changed tasks evenly over the projects without making to list too long.
This list is then rendered into the block with class "recentchanges" like this structure:
from reduced example
<h4>Link to project</h>
<ol>
<li>Link to changed task<span class=sub>Some details</span></li>
<li>Link to changed task<span class=sub>Some details</span></li>
...
</ol>
...
The actual rendering of the <li> is done by the
printChangeLine($c); which is defined in
lists/list_recentchanges.inc.php.