1Introduction
2============
3
4Unbound
5-------
6
7`Unbound`_  is  an implementation of a DNS resolver, that performs caching and
8DNSSEC validation.
9Together with unbound, the libunbound library is provided.
10This library can be used to convert hostnames to ip addresses, and back, as
11well as obtain other information.
12Since the resolver allows to specify the class and type of a query (A record,
13NS, MX, ...), this library offers powerful resolving tool.
14The library also performs public-key validation of results with DNSSEC.
15
16.. _Unbound: http://www.unbound.net/documentation
17
18pyUnbound
19---------
20
21The pyUnbound is an extension module for Python which provides an
22object-oriented interface to libunbound. 
23It is the first Python module which offers thread-safe caching resolver.
24
25The interface was designed with the emphasis on the simplicity of use.
26There are two main classes :class:`unbound.ub_ctx` (a validation and resolution
27context) and :class:`unbound.ub_result` which contains the validation and
28resolution results.
29The objects are thread-safe, and a context can be used in non-threaded as well
30as threaded environment.
31Resolution can be performed blocking and non-blocking (i.e. asynchronous).
32The asynchronous method returns from the call immediately, so that processing
33can go on, while the results become available later.
34
35Features
36--------
37
38* Customizable caching validation resolver for synchronous and asynchronous
39  lookups
40* Easy to use object interface
41* Easy to integrate extension module
42* Designed for thread environment (i.e. thread-safe)
43* Allows define and customize of local zone and its RR's during the operation
44  (i.e. without restart)
45* Includes encoding functions to simplify the results retrieval
46* Internationalized domain name (`IDN`_) support
47
48.. _IDN: http://en.wikipedia.org/wiki/Internationalized_domain_name
49
50Application area
51----------------
52
53* DNS-based applications performing DNS lookups; the caching resolver can
54  reduce overhead
55* Applications where the validation of DNS records is required
56* Great solution for customizable and dynamic DNS-based white/blacklists (spam
57  rejection, connection rejection, ...) using the dynamic local zone
58  manipulation
59