LEGO® Digital Designer (LDD)
Is a freeware computer program produced by the Lego Group as a part of LEGO
® Design by me. The program allows users to build models using virtual Lego bricks.
Mecabricks Workshop
LEGO Wheels Chart
LEGO Unit Converter
LEGO Model Scaler
Bricksafe Thumbnail Helper
The Blueprints
LEGO Gear Ratio Calculator
Swooshable Colorschemer
Swooshable Minifigscaler
Swooshable Fonttester

LDraw
Is an open standard for LEGO
® CAD programs that allow the user to create virtual LEGO® models and scenes. You can use it to document models you have physically built, create building instructions just like LEGO®, render 3D photo realistic images of your virtual models and even make animations.
LDD to POV-Ray
Converter is a simple application that allows you to convert LEGO
® Digital Designer model file into POV-Ray™ file format and enables rendering of the photo-realistic images of the model. Program converts LDD model file into POV-Ray scene file and generates all other include files necessary for rendering of the scene file.
POV-Ray
Is a very good tool for ray tracing. Used to create 3D graphics. The program uses an advanced scene description language (SDL). My main model rendering tool. Information about the POV-Ray program and a very good course with the basics of modeling the scenes can be found at povray.pl (in Polish)
SR 3D Bilder
An advanced CAD program for modeling Technic projects. Uses the LDraw library. An advanced CAD program for modeling Technic projects. Uses the LDraw library. Program support for LEGO
® PowerFunction and LEGO® Mindstorm electric cables, improved flex part management,  support for Piston - rod mechanism, Support for Linear Actuators and Shock Absorbers. Easy create and animate technic models, Hinges and Gears Support. Quick connecting hinges and rotating parts, and more.
Blender
Is the free and open source 3D creation suite. It supports the entirety of the 3D pipeline-modeling, rigging, animation, simulation, rendering, compositing and motion tracking, even video editing and game creation.
Stud.io 2.0 Beta
The second version of the Stud.io program is currently in the test version. Scene modeling interface has been improved, added "Instruction Maker" tool. The program has photorealistic hardware rendering options, but requires a NVIDIA graphics card.
Blueprint
A building instruction generator for LEGO
® Digital Designer. Requirements Java8 or better, OpenGL version 3.2 or better and Lego Digital Designer. Simple, fast and intuitive to use. Exports the manual in PDF, PNG and
Stud.io
Is the free and open source 3D creation suite. It supports the entirety of the 3D pipeline-modeling, rigging, animation, simulation, rendering, compositing and motion tracking, even video editing and game creation.
Mecabricks
Is the first online LEGO
® CAD program based on the WebGL technology. Contains project libraries and a database of blocks. A simple and fast rendering tool.
Busufl
Busufl is free JAVA application allowing LEGO
® Digital Designer native LXF files to by photo realistically rendered. Besides normal single rendering mode it also incorporates Multirender and Animated GIF modes. A common problem when running a program is to refer to the jvm.dll file in a different location. An error occurs then. The solution is:
1. Go to C:/Program files/java/jre{version_java}/bin
2. Create folder Server
3. Go to C:/Program files/java/jre{version_java}/bin/client folder
4. Copy all data of this folder into the new
C:/Program files/java/jre{version_java}/bin/Server

Bluerender
Is open source SunFlow rendering engine for LDD. Program requirements  Java8 or better and LEGO
® Digital Designer. One of the simpler ways to generate renderings from LXF formats. I recommend it for beginners in this topic. Bluerender uses a scene file to control how the image is rendered. Bluerender works with the default scene file scene.sc but you can modify the default file {LDD_project_name}.sc to include changes that you want to apply to all models or create a scene file for only one model. Details can be found here
LeoCAD
LeoCAD is a CAD program that uses the LDraw library for creating LEGO
® models. Program has intuitive interface that is designed to allow new users to start creating new models without having to spend too much time learning the application.