Documentation and Information

Ren'Py Documentation
Comprehensive guides and references for using the Ren'Py engine.

Python Documentation
Official documentation for the Python programming language.

The DDLC Website
Official site for Doki Doki Literature Club with updates and information.

The DDLC Plus! Website
Official site for Doki Doki Literature Club Plus! with updates and information.
Modding Template
Text Editors and IDEs

Sublime Text
Lightweight and versatile text editor with a free trial.

Notepad++
Open-source text editor with a plethora of plugins and features.

Visual Studio Code
Open-source text editor with a plethora of extensions and features.

Atom
Open-source text editor with a plethora of packages and themes.

PyCharm
Python IDE with a free community edition.

Vim
Highly customizable text editor with a steep learning curve. Not recommended for novice programmers.

Neovim
Modernized version of Vim with improved features and performance. Not recommended for novice programmers.
Music Libraries
The Official DDLC Music Sample List
If you wanted to know exactly what was used in making the DDLC soundtrack.
Amacha Music
Japanese library of liberty-free music.
Epidemic Sounds
Background music with samples cleared forever with subscription to service, as cheap as $9.99 USD.
r/Drumkits
Free community-made drumkits and random one-shot sample packs.
Spitfire Audio BBC Orchestra Discover
Free trial orchestration VST with tremendous versatility.
Pianobook
Community-made Kontakt Instruments (Free but some require paid Kontakt Player - Some instruments work with Sforzando Soundfont player.)
SoundshockAudio
Collection of free and premium Kontakt Player instruments.
Plugins4Free
Free VST collection.