OpenBullet is a web testing suite which has the ability to perform request towards the target web application. This software is used to scrape and parse data, automated pentesting, unit testing using selenium and other such operations.
Disclaimer: Performing (D)DoS attack on website that is not owned by you or the ones for which you do not have the proper authorisation is illegal. In such case, the developer of the tool is not responsible.
How to build this software-
Download Link: https://github.com/openbullet/openbullet