Fing is a command line tool for network and service discovery. It provides you a complete view of any network in a very short time. Its smart discovery automatically detects the network type and uses the best technique to scan it. The best results are achieved on Ethernet networks (including Wireless ones), where Fing is able to detect all network hosts, firewalled ones included. The service discovery feature quickly detects active TCP services on a target host or network. Fing is based on Look@LAN.
YAGF is a graphical frontend for the cuneiform and tesseract OCR tools. It lets you open already scanned image files or obtain new images via XSane (scanning results are automatically passed to YAGF). Once you have a scanned image you can prepare it for recognition, select particular image areas for recognition, set the recognition language and so on. Recognized text is displayed in an editor window where it can be spell-checked, corrected, saved to disk, or copied to clipboard. YAGF also provides some facilities for a multi-page recognition.
ARP Neighbor Cache Fingerprinter is a tool that provides a mechanism for remote operating system detection by extrapolating characteristics of the target system's underlying neighbor cache and general ARP behavior. Given the non-existence of any standard specification for how the neighbor cache should behave, several differences in network stack implementations can be used for unique identification. The main disadvantage of this tool versus traditional fingerprinting is that because it's based on a Layer 2 protocol instead of a Layer 3 protocol, the target machine that is being tested must reside on the same Ethernet broadcast domain (usually the same physical network).