We have a web-based calendaring application.  We now have two objectives.  

The first objective is to out-task our existing buggy Outlook 2003 synchronizer to a different application that already provides Outlook synchronization.  In other words, we would much prefer to sync with some other app using some common format, such as iCal, rather than to continue having to maintain and debug our own Outlook Synchronizer and have to stay knee deep in Microsoft-based technologies.  Our core competency is in Java and its related web application technologies and that's where we'd rather spend our development time.

Our second objective is to be able to sync with Google calendar, because it already has mobile implementations that we would like to piggy-back of.

We thought we could accomplish both objectives by making ourselves iCal format compatible, which is something we anyway wanted to do due to a multitude of user requests.  Well, we just implemented iCal export and while, like I said, that's something both us and our users are very excited about, it didn't seem to solve either problem.

Here's why.

It turns out that if I subscribe my Google calendar to an iCal-compatible calendar, such as ours, it becomes read-only and I cannot update it in Google at all.  The only way it's not read-only is if you subscribe to another Google calendar and properly set the sharing options.  But a third-party calendar inevitably becomes read-only.  That's problem #1.

Problem #2 is that even this one-way ability to see my Skoach (that's the name of our app) tasks in Google doesn't work properly.  It brings in the information properly the first time when I sign up the google calendar to url of the iCal formatted Skoach file.    But subsequently, Google doesn't reflect the updates, when the information in that file changes.

So, it sure looks like Google might not be the answer to our Outlook Sync needs and even to our mobile sync needs.   Any advise?  Is there perhaps another prominent product or service that syncs with Outlook and with which we can "iCal synchronize" both ways?  And, if not,  is there another product or service that has a solid Outlook Sync which would be easy for us to sync with (even if it's not via iCal) ?