These are some alternative processing websites in case you run into problems with your installation or use of Processing.
I have not examined them 100% regarding the pros and cons.
Tutorials Point Delete code between <script> </script> and add your codes there instead.
codepen.io In order to use codepen, you'll need to type the following script. Then type your processing code between it.
<script type="application/processing"> </script> <canvas> </canvas>