Add a java interactive tutorial
Merge pull request #996 from esparta/master

[en] Adding Python book
Add PDF mention
Cleaned up Django version issue + added versions to Flask and Pandas.
Merge pull request #997 from Kentoseth/master

Cleaned up Django version issue + added versions to Flask and Pandas.
Added version numbers for all python topics where versions were accessible.
Merge pull request #998 from Kentoseth/master

Added version numbers for all python topics where versions were accessible.
Merge pull request #1 from vhf/master

update fork
Added a few Mathematics books and a few HDL (Verilog, VHDL) Books
Added a few Linux books
Merge pull request #999 from omarayad1/master

Added a Few Mathematics Books and HDL (Verilog, VHDL) Books
Create C# and Visual Basic section from .NET section (close #878)

Removed Nemerle because link is broken.
Merge pull request #1001 from sru/master

Create C# and Visual Basic section from .NET section (close #878)
Add Introducción a Rails to the list of spanish books.

This book is a spanish translation of the official guide "Getting Started
with Rails."
Merge pull request #1003 from jbranchaud/add-intro-a-rails

Add Introducción a Rails to the list of spanish books.
add TLA book by Leslie Lamport
add the index for TLA
Merge pull request #1004 from AndriyLin/master

[init] - TLA
Add Groovy/Gradle/Grails documents in Japanese.
Merge pull request #1006 from sudoyu/patch-1

Add Groovy/Gradle/Grails documents in Japanese.