MySQL is an open-source relational database management system (RDBMS). The SQL acronym stands for Structured Query Language. The MySQL development project has made its source code available under the terms of the GNU General Public License, as well as under a variety of proprietary agreements. MySQL was owned and sponsored by a single for-profit firm, the Swedish company MySQL AB, now owned by Oracle Corporation. MySQL is a popular choice of database for use in web applications, and is a central component of the widely used LAMP open source web application software stack (and other "AMP" stacks). LAMP is an acronym for "Linux, Apache, MySQL,Perl/PHP/Python."
Ruby on Rails, often called RoR or simply Rails, it's an open source framework for web applications written in Ruby
Ruby is a dynamic, reflective, object-oriented, general-purpose programming language
Django it's an open source framework for web applications development, written in Python