[Verizon Samsung Galaxy S III] vmancini3:
That file was/is an init.d script that is set to perform certain tweaks upon boot. Some of them seem to be tweaks to the dalvik vm, as well as other tweaks for the read ahead of the internal and external memory. There also seems to be a tweak in there that keeps the launcher in memory and allows it to use 2gb of RAM while doing so...

Here's what's in the file....

#!/system/bin/sh
######################
#Bean's System Tweaks#
######################
# io scheduler for intsd
echo "0" > /sys/block/mmcblk0/queue/rotational;
echo "512" > /sys/block/mmcblk0/queue/nr_requests;
echo "2048" > /sys/block/mmcblk0/queue/read_ahead_kb;
# io scheduler for extsd
echo "0" > /sys/block/mmcblk1/queue/rotational;
echo "512" > /sys/block/mmcblk1/queue/nr_requests;
echo "2048" > /sys/block/mmcblk1/queue/read_ahead_kb;
# tcp/ip tweaks
echo "4096 87380 16777216" > /proc/sys/net/ipv4/tcp_wmem;
echo "4096,87380,16777216" > /proc/sys/net/ipv4/tcp_rmem;
echo "16777216" > /proc/sys/net/core/wmem_max;
echo "16777216" > /proc/sys/net/core/rmem_max;
echo "256960" > /proc/sys/net/core/rmem_default;
echo "256960" > /proc/sys/net/core/wmem_default;
echo "0" > /proc/sys/net/ipv4/tcp_timestamps;
echo "1" > /proc/sys/net/ipv4/tcp_tw_reuse;
echo "1" > /proc/sys/net/ipv4/tcp_tw_recycle;
echo "1" > /proc/sys/net/ipv4/tcp_sack;
echo "1" > /proc/sys/net/ipv4/tcp_no_metrics_save;
echo "1" > /proc/sys/net/ipv4/tcp_window_scaling;
echo "5" > /proc/sys/net/ipv4/tcp_keepalive_probes;
echo "30" > /proc/sys/net/ipv4/tcp_keepalive_intvl;
echo "30" > /proc/sys/net/ipv4/tcp_fin_timeout;
#battery
echo "1000" > /proc/sys/vm/dirty_expire_centisecs;
echo "2000" > /proc/sys/vm/dirty_writeback_centisecs;
#buffer tweaks
setprop net.tcp.buffersize.default 4096,87380,704512,4096,16384,704512;
setprop net.tcp.buffersize.wifi 4096,221184,3461120,4096,221184,3461120;
setprop net.tcp.buffersize.lte 4094,221184,3461120,4096,221184,3461120;
setprop net.tcp.buffersize.umts 4094,87380,393216,4096,16384,393216;
setprop net.tcp.buffersize.hspa 4092,87380,704512,4096,16384,393216;
setprop net.tcp.buffersize.hsupa 4092,87380,704512,4096,16384,393216;
setprop net.tcp.buffersize.hsdpa 4094,87380,704512,4096,16384,393216;
setprop net.tcp.buffersize.hspap 4092,87380,704512,4096,16384,393216;
setprop net.tcp.buffersize.edge 4093,26280,35040,4096,16384,35040;
setprop net.tcp.buffersize.gprs 4092,8760,11680,4096,8760,11680;
setprop net.tcp.buffersize.evdo_b 4094,87380,393216,4096,16384,393216;
#launcher
setprop windowsmgr.support_rotation_270 true;
#Keep Launcher in Memory
setprop ro.HOME_APP_ADJ 1;
setprop ro.HOME_APP_MEM 2048;
#IPv6 Privacy Extensions
sysctl -w net.ipv6.conf.default.use_tempaddr=2;
sysctl -w net.ipv6.conf.all.use_tempaddr=2;
#after x seconds a new ipv6 address is obtained
sysctl -w net.ipv6.conf.all.temp_prefered_lft=3600;
sysctl -w net.ipv6.conf.default.temp_prefered_lft=3600;
# kill old garbage market doesnt clean
busybox rm -f /cache/*.apk;
busybox rm -f /cache/*.tmp;
busybox rm -f /cache/recovery/*;
busybox rm -f /data/dalvik-cache/*.apk;
busybox rm -f /data/dalvik-cache/*.tmp;
busybox rm -f /data/system/userbehavior.db;
busybox chmod 400 /data/system/usagestats/;
# ignore cwm blobs
if [ -e /data/media/clockworkmod ]; then
/sbin/busybox touch /data/media/clockworkmod/.nomedia;
/sbin/busybox touch /data/media/clockworkmod/backup/.nomedia;
/sbin/busybox touch /data/media/clockworkmod/blobs/.nomedia;
fi;
# ignore beans folder
if [ -e /data/media/jellybeans ]; then
/sbin/busybox touch /data/media/jellybeans/.nomedia;
fi;
# make sure everything still has noatime
busybox mount -o remount,ro,noatime,noauto_da_alloc,nodiratime,barrier=0,nobh /system;
busybox mount -o remount,noatime,noauto_da_alloc,nodiratime,nodev,barrier=0,nobh /data;
busybox mount -o remount,noatime,noauto_da_alloc,nodiratime,nodev,barrier=0,nobh /cache;
sync;