I've made alts to this as well to include date due, days to go and assignee. Also altered the sort order to be by date due. Normally I wouldn't make changes like this to 3rd party software because of having to keep track of the changes on upgrades as mentioned earlier. But I really needed to be able to order by date for tickets we are working on.
Using V1.1.3 Made alterations to:
activecollab/application/modules/tickets/models/tickets/Tickets.class.php
: Changed order by to be due_on DESC instead of priority in each of the uses:
'order' => 'due_on ASC',
or to order by priority and then date
'order' => 'priority DESC, due_on ASC',
activecollab/application/modules/tickets/views/tickets/index.tpl
Included dates and responsible in output
<td class="name">
<a href="{$ticket->getViewUrl()}">{$ticket->getName()|clean}</a>
<span class="details block">{object_assignees object=$ticket}</span>
</td>
<td class="name">
{$ticket->getDueOn()|date:0}
<span class="details block">{if $ticket->getDueOn()}{due object=$ticket}.{/if}</span>
</td>
public/assets/tickets/stylesheets/main.css
Altered the task name - td.name font colour to be same as in assigment