Clementine - Free,Open Source,Modern music player.
AIMP - Free Audio player with support of large number of formats and playlists.
Audacious - Free,Opensource audio player with a focus on low resource use with wide range of audio formats.
Video Convertor -
HandBrake - Opensource Video Convertor with widely supported codec.
Video Editor -
OpenShot - An Award-winning free and open-source video editor for Linux,Mac and Windows,Create videos with exciting video effects,title,audio tracks and animations.
Kdenlive - free and open-source video editing software based on the MLT Framework,KDE and QT.
Graphics tool -
Gimp - A cross-platform image editor available for Windows,Linux & alternative for Adobe Photoshop.
Inkscape - A Open-Source professional vector graphics editor for Windows,Linux & Mac.
Krita - A free-software and an open-source raster graphics editor designed primarly for digital painting and animation purposes.
Paint.Net - A raster graphics editor program for Microsoft Windows.
Blogging tool -
Open Live Writer - A powerful,lightweight blog editor that allows you to create blog posts,add photos and videos . it Supports Blogger.com,WordPress..etc.
Riot - A Small and powerful real time image optimization tool.
Office Suite -
LibreOffice - An Open-Source Microsoft Office Alternative the best you can get.
Kingsoft Office - includes free word processor, spreadsheet and presentation software with MS office compatible.
PDF Reader -
Adobe Acrobat Reader DC - free global standard for reliably viewing,printing and commenting on PDF documents.
Sumatra PDF - Powerful,Small,portable and start up very fast.
