They don't support open-source options for database, LDAP and more (MySQL, OpenLDAP).
You need relatively current client and server OS software -- NT and Windows 98 aren't supported BUT that shouldn't be an issue for most companies at all. It needs WebSphere 5.0 or later in the IBM documentation.
Is the accurate? I don't know. In the past, WebSphere Portal has been much more problematical to configure (ONLY specific fix packs of related software modules were supported. If you had Portal server 4.11, you needed fix pack X on DB2 version 8.1 for instance -- anything else would fail.
Based on the documented standard of WebSphere Portal 5.0, I assume all IBM Portlets are written to the old IBM Portlet API standard, not the new open standard (JSR168). That's only supported in WebSphere Portal 5.02 and later releases. Do you really want to write to the old Portlet API? In most cases, probably not. Can you use the new API IF you can run Workplace 2.0 on IBM WebSphere Portal 5.02? Probably, but I haven't tried it.
The marketing information says it's standards-based. Other WebSphere products support standards BUT add custom extensions that can lock your application into running on WebSphere or DB2 only. Due diligence requires identifying those limitations carefully -- what are the added proprietary software extensions you need to buy (DB2 Extenders etc).
How does it compare to other options including the open-source ones? We're doing collaboration now for our business using a variety of open-source tools and billable third-party services that let us do Web-based training, project teams, mentoring and more. You probably want to compare Workplace 2.0 to other options. IBM reviews don't always find the right options to compare to as well.
This is only a start on ideas.
This was first published in June 2004