I know I am late to the party, but I can't believe no one has mentioned Qt Creator
It is truly available for all major platforms (exact same environment on Linux, Windows, Mac, others); indeed, Qt is the premier cross-platform development environment.
For your project i think it will be better to use C# (I dont really know it but i think it look like C).
Python is an interpreted language. So for me it's good for make some small script or think like that but if you want to create a solid application you better use compilated language.
I created a script called Knock to convert ACSM files to DRM-free EPUB files at the command line:
[user@computer:~]$ knock my-book.acsm
Downloading the EPUB file from Adobe...
Decrypting the file...
DRM-free EPUB file created:
The script is gratis and libre. This isn't a client/reader per se, it just let's you convert the ACSM file to a DRM-...
The only product I get in mind is Apache OFBiz. This product will offer you a lot of options, it is web based, but it's not so sample and need effort to be customized for your needs (it is not ready to use for your purpose).
Because it is Java based you can run it on (almost) any operating system.
I'd recommend to use the Google API for speech recognition:
To test it online: https://cloud.google.com/speech-to-text
Supported languages: https://cloud.google.com/speech-to-text/docs/languages (it supports Hindi)
You can call it via Python or some other language on Linux.
FYI Is there any decent speech recognition software for Linux?