Imagemagick

You can convert an image sequence into a gif by using the convert command on imagemagick. The convert command takes all files in the current folder with the .png extension and converts them into a single gif with a specified name. The delay between frames is given in milliseconds. Files should make use of frame padding with leading zeroes to be effectively converted in the correct order. The convert command shown below is the direct command in the CLI and does not need to be pre-pended by the program name.

convert -delay <DELAY_AMOUNT> -loop 0 *.png <GIF_NAME>.gif