and experience:
Performance
Arachni's HTTP stack has the time-proven cURL library at its core and utilises asynchronous requests in order to squeeze out every little bit of your available resources.
In addition, the High Performance Grid allows you to combine the resources of multiple nodes for lightning fast scans.
Intelligence
In order to compensate for the widely heterogeneous environment of the WWW Arachni utilises a combination of widely deployed techniques (taint-analysis, fuzzing, differential analysis, timing/delay attacks) along with novel technologies (rDiff analysis, modular meta-analysis) developed specifically for the framework.
This allows the system to make highly informed decisions using a variety of different inputs; a process which diminishes false positives and even uses them to provide human-like insights into the inner workings of web applications.
Automation
Arachni is a fully automated system which tries to enforce the fire and forget principle. As soon as a scan is started it will not bother you for anything nor require further user interaction.
Upon completion, the scan results will be saved in a file which you can later convert to several different formats (HTML, Plain Text, XML, etc.).
Flexibility
The system allows for multiple deployment options ranging from a Ruby library for highly customized scripted scans, to a simple single-user single-scan command line interface, to a multi-user multiple/parallel-scan distributed deployment, to a global High Performance Grid deployment for lightning fast scans.
And best of all, the deployment time for any of the above ranges from instant to a few minutes.
Openness
Arachni is distributed under the Open Source General Public License v2
which provides you with the ablility to inspect the code at will.
It also means that you can change and modify the system to fit your every need.
Moreover, control of all distributed components is facilitated via a simple and open Remote Procedure Call protocol in an effort to increase interoperability and cross-platform compliance.
Extendability
Most aspects of Arachni are plugable components; from the security checks (modules), to the reports, to the entities which extract paths from source code (path extractors) and to its meta-analytical skills.
Furthermore, the system can be indefinately extended to perform abstract operations via the addition of plugins.