GNU Libidn is an implementation of the Stringprep, Punycode, and IDNA specifications defined by the IETF Internationalized Domain Names (IDN) working group. It is used to prepare internationalized strings (such as domain name labels, usernames, and passwords) in order to increase the likelihood that string input and string comparison work in ways that make sense for typical users throughout the world. The library contains a generic Stringprep implementation that does Unicode 3.2 NFKC normalization, mapping and prohibition of characters, and bidirectional character handling. Profiles for iSCSI, Kerberos 5, Nameprep, SASL, and XMPP are included. Punycode and ASCII Compatible Encoding (ACE) via IDNA are supported.
Avahi is a framework for Multicast DNS Service Discovery (mDNS/DNS-SD a.k.a. Zeroconf) on Linux. It allows programs to publish and discover services running on a local network with no specific configuration. For example, you can plug into a network and instantly find printers to print to, files to look at, and people to talk to.
namebench finds the best DNS servers to use for your machine, benchmarks them, and outputs pretty graphs to tell you why they are optimal. It supports multiple data sources such as Alexa, your browser history, or tcpdump replays in order to generate the most relevant and individualized recommendation.
dnspython is a DNS toolkit for Python. It supports almost all of the record types. It can be used for queries, zone transfers, and dynamic updates. It supports TSIG authenticated messages and EDNS0. dnspython provides both high and low level access to DNS. The high level classes perform queries for data of a given name, type, and class, and return an answer set. The low level classes allow direct manipulation of DNS zones, messages, names, and records.
Chaosmap is an information gathering tool and DNS, Whois, and Web server scanner. It can be used to look up DNS names with a dictionary with or without using a salt. Salting for DNS means it will append numbers from 1-9 to the name in the dictionary with or without a - and _ or a leading 0. Salting for Web stuff will try double slashes and some directory traversal tricks. It performs reverse DNS lookups of a whole IP range (with optional Whois lookup) and dictionary scans for hidden paths on one Web server or a range of IP addresses. Optionally you can encode a path with URL encoding use Google dict lookup mode to find the path on Google and only query the Webserver if there are no search results. It can also extract email addresses from domains using a Google search or perform a list of Google Hacking queries on your domain.
ext-Dns is a core library, an extensible forward DNS server, and some additional tools designed to create DNS server solutions which are able to do any additional operation at the resolution level (running commands, rewritting replies, gathering stats, and so on), without any limit. It provides a ready-to-use solution in case you want to build a DNS server which takes additional actions at the resolution level in an easy way. That is, its design is focused on allowing people to implement whatever they like when a request is received, freeing them from most of the details which involves handling DNS protocol.
CyberDNS is a Web application to manage DNS zones and BIND configurations easily. It lets you add entries and then watch as they are generated into zone and configuration files. It supports IPv6 and most DNS types. The Web interface runs on the master DNS server, and cron is used to synchronize the Sqlitedb and zone files to slave DNS servers. It is easy to make snapshots to revert in the event of failure.