procps-3.1.1 --> procps-3.

vmstat -s
vmstat -f
top handles old (and future) config files
w is way faster
top's B toggle
top's t fixed    <--- minor bug
top several times faster
out-of-bounds RT as "RT"
general C99 clean-up
watch: don't drop empty lines   <--- minor bug
watch: re-indented
ps: smaller (was it 1 kB or 2 kB ?)
ps: fewer globals
ps: hardware-enforced buffer protection
some seLinux fixes    <--- minor bug
top: old sort keys
top: man page tweak

procps-3.1.0 --> procps-3.1.1

vmstat faster on 2.5.xx kernels
vmstat header fixed
vmstat -a re-fixed

procps-3.1.0 --> procps-3.1.0

vmstat displays IO-wait time instead of bogus "w"
can build w/o shared library (set SHARED=0)
when IO-wait hidden, count as idle, not as sys
pmap command added (like Sun has)
do not crash GNU make 3.79
top slightly faster

procps-3.0.4 --> procps-3.0.5

top tolerates super-wide displays
better (?) RPM generation
XConsole and top.desktop removed
old build system removed
code cleanup
pgrep and pkill get "-o" (oldest matching process)
had vmstat "bi" and "bo" output interchanged on 2.5.xx
fix man page tbl directives
top man page cleaned up

procps-3.0.3 --> procps-3.0.4

make top go faster
Linux 2.2.xx ELF note warning removed
only show IO-wait on recent kernels
fix top's SMP stats
fix top for "dumb" and "vt510" terminals
in top, limit the priority values to -99 ... 99

procps-3.0.2 --> procps-3.0.3

more "make install" fixes
lib CFLAGS working again
top.1 codes fixed
bad (int*) cast in top removed
top runs faster
libproc memory corruption fixed
rant moved out of top.1 man page
ability to SKIP installing things
fixed ps --sort crash

procps-3.0.1 --> procps-3.0.2

top defaults to the old layout
top defaults to sorting by %CPU
fix top for non-SMP 2.2.xx and 2.0.xx
new "make install" fixed
vmstat -a fixed
vmstat compiles with latest gcc-3.x
vmstat does 64-bit time

procps-3.0.0 --> procps-3.0.1

sysctl handles net/ipv4/conf/eth1.0123/tag (VLAN interface)
sysctl handles net.ipv4.conf.eth1/0123.tag (VLAN interface)
"ps" is now about 2x faster than in procps-2.x.x
"ps -F" now documented
w works in KOI8-R locale
vmstat documentation update
"skill -n blah blah blah" lets you test options
simple "make && make install" now

procps-2.x.x --> procps-3.0.0

designed to support Linux 2.0 through 2.5.41 and beyond
new top, with optional: color, windowing, SMP stats
runs faster
more "it crashes" bugs fixed
top shows IO-wait time
vmstat can show active/inactive memory stats
real-time info supported in ps
correct "ps -o size" and "ps --sort size"
new maintainers
reduced memory usage for ps
allow large PIDs to be specified
SELINUX support is just a recompile away
the "F" column shrank, so "ps -l" has more command name room
64-bit time reduces the overflow problem
support S/390, IA-64 emulator, and user-mode Linux
oldps is gone
configure script -- use "make -f Makefile.noam" as a backup
"w" program better at determining what a user is doing
more stable
code at http://procps.sf.net/ now (SourceForge)

Earlier changes, for those not using Debian already:

more stable
runs faster
-F format option
better error reporting in ps for unknown format specifiers
BSD's sysctl options -b and -X
top displays well on large-memory systems
old BSD-style select-by-PID ("ps l$$")
15-character user names
ps 'f' ASCII art forest fixed
add SIGSYS on i386
top reports real RSS value
large-memory systems work
minimal ps program for embedded systems (minimal.c)
BSD personality process selection fixed
support locale (French) with ',' and '.' mixed up
pgrep program
includes the "kill" and "nice" programs
don't chop non-tty ps output at 80 columns