Free very easy to software for linux

Very Simple Network Monitor is a complete rewrite of project PHP Monitoring.
Its by default capable of monitoring via ping, UDP and TCP checks. Has builtin plugin system so customized scripts can be used to monitor whatever you like eg. oracle tablespaces, diskspace whatever; Alarms are also generated via plugins, it has standard EMAIL alarm, but can be customized to have snmp traps, or sms gateways or whatever.
Can store uptime reports in mysql and generated reports and uptimes in % availability per service.
Has one centralised html monitoring page with all alarms together for good overview.
Enhancements:
- reporting bug fixed
- alarm causes nmonitor to be locked bug fixed
- some other minor stuff I cant remember
- removed some typos from INSTALL doc:)

Very restrictive set of firewall rules script is a sample firewall for ip_tables, the tool for doing firewalling and masquerading under the 2.3.x/2.4.x series of kernels.

Be warned, this is a very restrictive set of firewall rules (and they should be, for proper security). Anything that you do not _specifically_ allow is logged and dropped into /dev/null, so if youre wondering why something isnt working, check /var/log/messages.

This is about as close as you get to a secure firewall. Its nasty, its harsh, and it will make your machine nearly invisible to the rest of the internet world. Have fun.

To run this script you must chmod 700 iptables-script and then execute it. To stop it from running, run iptables -F

Sample:

#Point this to your copy of ip_tables
IPT="/usr/local/bin/iptables"

#Load the module.
modprobe ip_tables

#Flush old rules, delete the firewall chain if it exists
$IPT -F
$IPT -F -t nat
$IPT -X firewall

#Setup Masquerading. Change the IP to your internal network and uncomment
#this in order to enable it.
#$IPT -A POSTROUTING -t nat -s 192.168.1.0/24 -j MASQUERADE
#$IPT -P FORWARD ACCEPT
#echo 1 > /proc/sys/net/ipv4/ip_forward

#Set up the firewall chain
$IPT -N firewall
$IPT -A firewall -j LOG --log-level info --log-prefix "Firewall:"
$IPT -A firewall -j DROP

#Accept ourselves
$IPT -A INPUT -s 127.0.0.1/32 -d 127.0.0.1/32 -j ACCEPT
#If youre using IP Masquerading, change this IP to whatever your internl
#IP addres is and uncomment it
#$IPT -A INPUT -s 192.168.1.1/32 -d 0/0 -j ACCEPT

#Accept DNS, cause its warm and friendly
$IPT -A INPUT -p udp --source-port 53 -j ACCEPT
$IPT -A INPUT -p tcp --source-port 113 -j ACCEPT
$IPT -A INPUT -p tcp --destination-port 113 -j ACCEPT

#Allow ftp to send data back and forth.
$IPT -A INPUT -p tcp ! --syn --source-port 20 --destination-port 1024:65535 -j ACCEPT

#Accept SSH. Duh.
#$IPT -A INPUT -p tcp --destination-port 22 -j ACCEPT

#Send everything else ot the firewall.
$IPT -A INPUT -p icmp -j firewall
$IPT -A INPUT -p tcp --syn -j firewall
$IPT -A INPUT -p udp -j firewall

Aranha is an application that uses an XML-RPC layer to retrieve information from one or more servers. The type of information gathered is implemented via plugins, and can be displayed or archived in several different ways.

The data is gathered in Round Robin Databases (integrated with rrdtool) and can be accessed using a XUL interface available from the system. Plugins are very easy to write.

Configuration

To configure this module, either pass specific configuration values to
Makefile.PL like this:

perl Makefile.PL CONFIG_VAR="config val"
or
edit the %DEFAULTS variable on the toplevel Makefile.PL

Installation

To install this module type the following:

perl Makefile.PL
make
make test
make install

Neural Network Framework project is a C++ framework to develop, simulate, and analyze arbitrary complex neural networks.
The programmer can use the classes provided to create neural networks with arbitrary topology and mixed type of neurons. Its very easy to add customized neurons and layers.
Enhancements:
- A ScaleFunction that scales the input vector of a Cluster and a normalize method for RealVec were added.
- Two methods were added to the Random class to randomize RealVec and RealMat.

RateIt is a GUI tool for performing subjective testing of audio samples based on the MUltiple Stimuli with Hidden Reference and Anchor (MUSHRA) methodology as specified in ITU-R recommendation BS.1534-1.

This project is dual-licensed under the General Public License (GPL) and the Mozilla Public License (MPL) version 1.1.

RateIt is written in C using libglade, which means that the user interface is very easy to customise. It currently uses sox for playback but support for libsndfile is planned (patches welcome).