The listed tools and applications are useful in academic learning and research activities.
1. Mendeley
Mendeley is a product of Elsevier available freely. It allows to search and sort the references, e-documents and notes in one place. Apart from these features, Mendeley provides a very strong literature survey and compilations of bibliographies. Follow and Download Mendeley at https://www.mendeley.com/
2. Docear
Docear is a unique solution to academic literature management, i.e. it helps you organizing, creating, and discovering academic literature. Docear offers;A single-section user-interface, ‘literature suite concept‘, A recommender system. Docear can be downloaded from http://www.docear.org/
3. GNU Octave
GNU Octave may be the best-known alternatives to MATLAB. Octave is licensed under the GPL, and its source code can be found on the GNU FTP site. Find more about GNU Octave and download here at https://www.gnu.org/software/octave/
4. Scilab
Scilab is an open source solution for numerical computing which runs across all of the major software platforms: Windows, Mac, and Linux. Scilab is known as the best alternative and similar to MATLAB in its implementation. Download Scilab here at https://www.scilab.org/
5. Gretl
Gretle is a cross-platform software package for econometric analysis, written in the C programming language. It is free, open-source software. It can be redistributed, modified under the terms of the GNU General Public License (GPL) as published by the Free Software Foundation. Know more on Gretle and download software from http://gretl.sourceforge.net/