Open-AudIT is an application to tell you exactly what is on your network, how it is configured and when it changes. Open-AudIT will run on Windows and Linux systems. Essentially, Open-AudIT is a database of information, that can be queried via a web interface. Data about the network is inserted via a Bash Script (Linux) or VBScript (Windows). The entire application is written in php, bash and vbscript. These are all 'scripting' languages - no compiling and human readable source code. Making changes and customisations is both quick and easy.
Windows PCs can be queried for hardware, software, operating system settings, security settings, IIS settings, services, users & groups and much more. Linux systems can be queried for a similar amount of information. Network devices (printers, switches, routers, etc) can have data recorded such as IP-Address, MAC Address, open ports, serial number, etc, etc. Output is available in PDF, CSV and webpages. There are export options for Dia and Inkscape.
Open-AudIT can be configured to scan your network and devices automatically. A daily scan is recommended for systems, with network scans every couple of hours. That way, you can be assured of being notified if something changes (day to day) on a PC, or even sooner, if something "new" appears on your network.
Can you really afford not to know what's on your network ?
Open-AudIT v4.0.1 releasedv4.0.1 has been released for Windows and Linux!
Make sure you checkout the release notes (especially Windows users and doubly so if upgrading). And don't forget about the wiki for all the documentation. Grab v4.0.1 from the downloads page.