Opera 4.0: Public Beta 3 is now available

Two good resources are also the feature request site and the known issues.

Btw, Opera will also ship as the default browser for Psion PDAs in the future.

It supports XML! (more about XML from Opera)

From another release:
" Opera 4.0 Upgrades File Exchange: Includes HTTP 1.1
..
HTTP 1.1 is the name of the latest version and it is included in Opera 4.0.

doing more, doing it faster
Who cares that the language of Web communication is changing? You do -- Because this version of HTTP provides higher end-user performance.
It does more and it does it faster. This is great for web surfers and especially good for Opera users, because Opera 4.0 has HTTP 1.1.

prevents eavesdropping of passwords
It is also more secure. HTTP 1.1 is more secure because while you authenticate yourself, it does not allow eavesdropping.
This is an important step, increasing security on the web.

give me something faster
Security is great. I’m glad my passwords aren’t being passed around. Yes, and Opera is very secure (we’ll save that for another time).
Opera with HTTP 1.1 is even faster.

HTTP 1.1 is faster because it allows persistent connections. Persistent connections benefit networks and end-users.
HTTP 1.1 increases performance by allowing persistent connections; pipelining, caching, and IP address preservation.
..
Pipelining allows Opera to make multiple requests without waiting for an answer.
Basically it is the difference between calling someone multiple times asking for different items versus calling once with a list.
A list is obviously more efficient!

Chunking is the splitting up of documents. Once chunked the document can be sent over a persistent connection through a pipeline.
Each chunk is a known length so by splitting up the document in chunks even documents that have no known length can be sent.

headers used for cache verification have been expanded
There is more cache control. Opera is served more details. These details expand the caching capabilities because they allow more information to be held.
Information like how old a document is, how long before it should be refreshed, or if it should be checked every time.

HTTP 1.1 Under the Hood
HTTP 1.1 has furthered the speed of Opera.
Opera is serving you documents faster, and with HTTP 1.1 increasing the general efficiency of the Web.
It is relieving congestion and utilizing better methods of caching.
Additionally, it is providing a little extra security when sending your passwords. HTTP 1.1 is a great item to have under the hood in Opera 4.0."

Sounds great, doesn't it?
Check it out.
Feel free to disagree, but I think Opera did more for standards then MS and Netscaper/AOL together the last two years.