People often ask 'Is Webware ready for prime-time use?' or 'Can Webware really handle it?' The answer is yes, but this is the wrong question.
A better question would be 'can Webware help me build an application that can reliably handle heavy loads?' Webware is not an application, methodology, or recipe for success. It is a development framework and a collection of useful tools. If you use the framework and tools intelligently, and design your application well, then yes it will help you build an application that can reliably handle heavy loads. If you use them poorly, or botch your application design, don't cross your fingers.
An even better question is 'does Webware's architecture encourage and facilitate effective application designs?' I believe it does, for the following reasons:
it uses Python: a well designed, modular, object-oriented, easy to learn, and easy to maintain language
it is thoroughly object-oriented and encourages object-oriented applications, unlike other frameworks like PHP and ColdFusion, which tend to spawn a maze of spaghetti code and include files.
it is fairly simple to understand and very fast to develop with once you've groked it. This encourages rapid prototyping and testing, and helps weed out bad designs early on. Webware is a great fit for software engineering methodologies such as eXtreme Programming and Agile methods.
it doesn't dictate how you handle data storage and object persistence.
it is extremely portable, allowing you great flexibility in your choice of operating systems and other tools.
the Python and Webware user community is supportive, intelligent, and experienced. If you run into technical or conceptual hurdles, ask some smart questions and you'll get some real gems of clear thought in response.
objects (servlets, sessions, data caches) persist in memory between requests. This can lead to huge performance gains over other frameworks without in-memory object persistence.
it is extensible by design.
Drop by the Webware Propaganda for some more info.
Keep in mind that Webware is only one part of your toolkit. Non-trivial applications will rely on many other resources. These might include server and network hardware; operating system(s); persistence mechanisms, such as filesystems and databases; web servers(s); web caches, such as squid; external credit card processors; shipping processors; and, of course, web browsers. The performance and reliability of your application will depend on how you utilize these resources in conjunction with Webware.
Here's some notes on Using Webware Effectively.
-- TavisRudd - 30 Mar 2002
Have a look at some recent Webware benchmarks.
-- ChrisZwerschke - 18 Apr 2010