4. General Updates

OProfile is a system-wide Linux profiler, capable of running at low overhead. It consists of a kernel driver and a daemon for collecting raw sample data, along with a suite of tools for parsing that data into meaningful information. OProfile is generally used by developers to determine which sections of code consume the most amount of CPU time, and why.

Newer Red Hat disk images use the SHA-256 algorithm as the checksum method. Previously, verifying these checksums on Red Hat Enterprise Linux 4 was not a simple process. Red Hat Enterprise Linux 4.9 provides an updated coreutils package, containing checksum utilities for the whole SHA-2 family, allowing a user to easily count or verify SHA-224, SHA-256, SHA-384, and SHA-512 checksums.

KSH-93 is the most recent version of the KornShell (ksh) by David Korn of AT&T Bell Laboratories, a shell programming language upwards-compatible with sh (the Bourne Shell). In Red Hat Enterprise Linux 4.9, ksh is updated to the upstream release version ksh93t+.

Red Hat Enterprise Linux 4.9 features version 3.6.13 of the Mozilla Firefox open source web browser. Refer to the Firefox 3.6 Release Notes and Firefox 3.6.13 Release Notes for further details on the bug fixes and enhancements provided by this update.

SystemTap is a tracing and probing tool that allows users to study and monitor the activities of the operating system (particularly, the kernel) in fine detail. It provides information similar to the output of tools like netstat, ps, top, and iostat; however, SystemTap is designed to provide more filtering and analysis options for collected information.