The Google App Engine not only is getting a lot of press in a little time since it was unleashed less than a week ago, it's getting more demand than its original supply.

Google Friday invited 10,000 more developers to try it out after the company filled the 10,000 allotted accounts within a few hours after it was made available Monday night, wrote Google Product Manager Peter Koomen in a blog post. 

The software lets programmers build applications on top of Google's infrastructure, including BigTable and the GFS file system. The first iteration was written in Python, but there have been requests for Ruby, Hibernate, Java, Perl, PHP and FORTRAN, as well as bug fix requests.

Is any single Web app feature hotter than the capabilities to work with software offline? Google is working to augment App Engine to support offline processing for apps that need to perform scheduled tasks or larger-scale data migration.

Google also wants to support larger files; the App Engine currently imposes a limit of 1 megabyte for inbound and outbound processing requests, which isn't going to cut it for heavier apps.

Finally, Koomen noted billing for additional quotas as another feature request the company is focusing on. Here are the current limits, including 3 apps per developer, 500MB of storage per app, and per diem quotes such as 2,000 e-mails and 10,000MB of inbound and outbound bandwidth CPU.

"Although Google App Engine will always be free to get started, we plan on allowing developers to purchase additional resources in the future, while paying only for what they use," he wrote.

Spoken like a true utility computing provider. I'll be looking forward to see any mainstream apps that sprout up from the App Engine.