From time to time people ask me about what is the best cross-platform business suite of software. Here's the list:
For write, spreadsheets etc. it's still got to be Microsoft Office. Though if you want to pretend you're Steve Jobs, you'll have to make the final presentation in Keynote.
Calendars. If you're in a cross-platform environment, and can afford a Microsoft Exchange server (though there are now hosted options for a reasonable monthly fee) the best way to do calendaring within a group is still Outlook on the PC and Entourage on the Mac. I know there are other options, some documented on this blog. But none have the features that Exchange provides. Of course, you could get everyone in your company to convert to GMail and even sign-up for the Beta of GMail for domains.
Mail. I love GMail, despite any privacy concerns. It is the only mail program that I know of that treats to and from messages all together in conversation threads instead as disparate messages. Beyond GMail, I'm not particular, though I always seem to crash Outlook.
CRM. Customer Relationship Management software is what a contact manager should be. To me the basic distinction is that contact managers, like Outlook or Apple Address Book, are just flat files without the ability to create much if any in the way of relationships between records. CRM's, by contrast, let you interconnect and associate contacts in all sorts of ways--referrals, opportunities, projects, companies. At the small business level, the best product that I've seen is DayLite. It is far and away the best interface and besides, it's relatively inexpensive. But it's only Macintosh. On the PC side you're left with the horribly outdated GoldMine, as well as ACT. At our company we've been using what is the only cross-platform solution--a web-based CRM. In our case, this is Salesforce. It's expensive (we bought during a very good promotion). And very unfortunately, it only syncs to your computer if you've got a PC. If there was ever a reasons for businesses to scrap their PC's entirely and move wholly to a Mac platform, Daylite is that reason.
Mind Mapping. See previous post. I use Mind Manager.
Project Management. I think there's only one choice for cross platform and that's FastTrack Schedule. It's a good program, though with some quirks, notably some limitations in printing and zooming. Microsoft Project is such a big and expensive clunker and it's not cross-platform. They abandoned the Mac long long ago. Another option is the web-based Basecamp.