Apple has released Safari 5.1.2, an update of its web browser. You can obtain it via the Software Updates component of Mac OS X’s Systems Preferences app.
According to Apple, Safari 5.1.2 contains various improvements, including fixes that: improve stability; address issues that could cause hangs and excessive memory usage; address issues that could cause webpages to flash white; and allow PDFs to be displayed within web content. It’s a 47.1MB download and requires Mac OS X 10.6.8 or higher.