The spreadsheet editor might very well be the most difficult office productivity application to migrate online, and there are a couple of good reasons for this:

First, HTML was originally designed to publish textual information and tables were added as a way to format tabular data, not to develop complex spreadsheets, therefore online word processors today are an order of magnitude more advanced than online spreadsheet editors.

Second, some spreadsheets can embed complex calculations that would make a web browser slow to a crawl and are not easy to delegate to an online server. Translation: an online alternative to Excel is a long way off.

Nevertheless, if you’re looking for a simple way to manage tabular data and sum some columns up, a couple of options are emerging today. Among them, Num Sum offers what TrimPath describes as a free bite-sized, sharable social spreadsheets. Hardly an Excel killer, but a good start nevertheless. Many thanks to Rob Boothby at Innovation Creators for his excellent Web Office Directory of online services that pointed me to Num Sum and some other new services. There is also wikiCalc from Dan Bricklin, co-inventor of the spreadsheet. And I should finally mention Zoho WebSheet, which is currently under development but has been reviewed already by Stowe Boyd on Corante. If it’s as good as Zoho Writer, which was reviewed earlier, we might have something interesting there.

I will continue looking for alternatives, but my prediction is that application-specific solutions will be made to work first. For example, Intuit’s QuickBooks Online Edition provides spreadsheet views of accounting data, even though it’s not a generic spreadsheet editor. I would also expect Salesforce.com to provide better bulk data editing capabilities and more advanced calculation tools that combined would offer the functionality of a simple spreadsheet editor through a totally different user interface.