Okular - Okular is a universal document viewer based developed by KDE.
ttsMP3.com - ttsMP3.com is a web application that can convert your texts into audio MP3 audio files and vice versa.
Sumatra PDF - Sumatra PDF is a slim PDF/DjVu/EPUB/XPS/CHM/CBR/CBZ/MOBI viewer for Windows.
VoiceMaker - Voicemaker is a web application with which you can convert your texts into audio by simply importing the text onto the dedicated text box.
Foxit Reader - Foxit Reader is a free and light-weight multi-platform PDF document viewer.
NaturalReader - Main Feature: Full Common Functions: Read Text Files o Text files o MS Word files