Qt Creator - Qt Creator is a cross-platform C++, JavaScript and QML integrated development environment. It is the fastest, easiest and most fun experience a C++ developer could wish for.
Adobe Animate - Adobe Animate is a Flash, vector animation software.
NanoFL Editor - Flash-like animation and vector graphics editor.
Express Animate - Easily create stunning 2D animations using keyframes with this motion graphics software. Export to video, flash, GIF or HTML5. Free Download for Windows.
Wick Editor - The Internet's free and open-source creation toolkit.
KoolMoves - Inexpensive animation software that combines ease-of-use with powerful effects for creating high quality Html5, GIF, AVI, and SWF animations and mobile apps