Please check the new webfile functionality. You can now stream files from disk for downloads and this reduces the memory footprint of your web applications. Now it is more unlikely that your app crashes due to out of memory exceptions.
For file uploads, they go now to a temp file which you can than move to their final destination or delete. So check the WebUploadedFile class. If you call the old Data function, the file is read from disk to keep existing code working. The new Save method allows to copy the file to another destination. But as it seems to use Binarystream internally, you may get an IOException, so please handle that with try/catch.
Something more hidden, but working is the new constant TargetXojoCloud. It must have been there since the cloud plans came up. Still if you plan to use the cloud, you can have code different in case of running in the Xojo Cloud compared to running a local copy on your own machines. As the cloud option may come in r4 later this year, you could already So you now can use code like this:
#if debugbuild then
// in the debugger
#elseif TargetXojoCloud then
// on the cloud
// on your own server
Testing on Windows XP with the betas showed that IE 7.0 now causes the AllowUnsupportedBrowser event. So it may no longer be supported by Xojo.
By the way, recently _webSupport was discovered here. One of the internal modules, I presume. At least you can type _webSupport. and press tab in editor to see autocomplete suggesting method names. I bet that is a bug, but a line like this works:
dim s as string = _webSupport.GZipCompress("Hello", 9)
Of course this is unsupported and you should not use it. Probably it is needed internally for sending gzip compressed data to the browser. But we are curious and would love to see more internals, so we better understand how things work and way. Maybe we can ask Xojo engineers to talk more about how things work internally on the conferences?
For MySQL Database also the MultiThread property is gone as now all queries run threaded. We'll see what problems this may solve or create.