we need zimbra collaboration suite clone in PHP and MySQL which can run on windows platform easily.
Also we need to customize the zimbra clone for less complex tools. We might remove some of the unrequired features of zimbra.
There are few more office collaboration suites in our mind which also can be considered for final project.
In brief, we need following features:
> Realtime instant messaging
> Bug List
> Project Management
> Payroll Management
> Leave Management
>Employee Tracking & Monitoring
> Employee List
> News & Events
> and few more can be added as per the requirement before project finalization but all of them will not be of major issue nature.