FULL PRODUCT VERSION :
1.6.0_10-rc; Java HotSpot(TM) Client VM 11.0-b13

ADDITIONAL OS VERSION INFORMATION :
Linux tester-desktop 2.6.24-19-generic #1 SMP Wed Aug 20 22:56:21 UTC 2008 i686 GNU/Linux

EXTRA RELEVANT SYSTEM CONFIGURATION :
Ubuntu 8.04, Gnome+GTK

A DESCRIPTION OF THE PROBLEM :
HTML rendering provided by JEditorPane is too slow for some average size pages. This causes rather serious performance problems when displaying JavaDoc in NetBeans IDE.

  Comments from NB developpers:

saubrecht: it takes almost 10 seconds to show javadoc for String class on my winxp laptop as well. the html page for String class (and some other classes as well) is too big so it takes a lot of time to compute swingbrowser's preferred size (needed by its enclosing jscrollpane). feel free to file a bug againt JDK to make html rendering faster but i don't think there's anything we can do on our side
- http://www.netbeans.org/issues/show_bug.cgi?id=146633

jpokorsky: ad slowness) the pages are loaded and presented by JEditorPane from JDK. Thus you should file a performance bug against JDK.
- http://www.netbeans.org/issues/show_bug.cgi?id=145900

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Try to open a String javadoc in NetBeans. Steps:

0. Install NetBeans
1. Add Javadoc to a JDK platform in Tools>Java Platforms
2. Invoke Help>"JavaDoc Index Search", type "String" in the search field and press Enter

Alternatively, you can try to open the String JavaDoc page in the component...

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Javadoc for String is rendered in 5 seconds or faster (preferably) on average PC.
ACTUAL -
Javadoc for String is rendered in more than 10 seconds (20 on my PC, which is AMD Opteron Processor 148, 2GB RAM).

REPRODUCIBILITY :
This bug can be reproduced always.