Product review: .Net comes to WebSphere Portal
Mainsoft lets .Net developers build WebSphere portlets, and it allows WebSphere to talk to SharePoint, to boot
Once you've populated your portlet's frame with your intended controls, simply select Run from the IDE's menu. Visual Studio will compile your application, and Mainsoft's components will translate the CIL code to Java bytecode, package the results into a .war file, and deploy that to a WebSphere Portal application server for execution. (Another addition to the Visual Studio IDE is an entry on the options menu that allows you to configure the connection information to the target WebSphere Portal.)
And, yes, you can debug the portlet as it executes in WebSphere. Mainsoft instruments the generated bytecode so that lines of C# (or VB.Net) source are properly associated by the debugger to the corresponding Java bytecode. In other words, while you single-step through C# or VB.Net source, it's Java bytecode that's actually being executed. You have to be careful where you set break points. While I was testing this capability, I occasionally caused WebSphere to interpret the paused process as an unavailable portlet.
Where Mainsoft's Portal Edition connects ASP.Net to WebSphere, the SharePoint Federator brings Microsoft's SharePoint into the WebSphere tent. The Federator is more or less a pair of premade portlet templates that are added to the Visual Studio IDE when you install the Federator SDK. (Because the Federator SDK builds WebSphere portlets, to use it you must first install Mainsoft's Portal Edition.)
The two portlet templates are the SharePoint List Viewer portlet and the SharePoint Item Viewer portlet. Put the pair together, and you have what amounts to a database browsing kit, the database in this instance being a SharePoint site. The List Viewer portlet provides a WebDAV-style interface into a SharePoint site's data. It lets you navigate into SharePoint folders and subfolders, and select content within those folders in the same way you would do when normally connected to SharePoint.
Select an individual file – a text document, say – and the Item Viewer comes into play. Though it is called a viewer, it is not limited to simply reading or downloading documents, but operates with SharePoint's check-in/check-out protocols. You can configure the portlet to either download a selected document, or allow the user to work with that document directly on the SharePoint site.
The core engine of the two portlets is the SharePointDataControl. This is an ASP.Net control whose design-time wizard lets you configure the portlets' connection details to a SharePoint server. The wizard also lets you fine-tune how portlets query into the SharePoint data, including which rows and columns are fetched in response to a given user request.
Finally, a critical adjunct of the SharePoint portlets is Mainsoft's Credential Vault Web Control, which can capture a user's SharePoint login information and store it securely in WebSphere Portal's credential vault. Using the Credential Vault Control lets you create a single sign-on experience; when a user signs on to the WebSphere Portal, then activates one of the SharePoint viewer portlets, the user's SharePoint login information is invisibly fetched from the vault. The user is securely logged in to the SharePoint site with no overt action required.