Brutaldon is an alternative FOSS client for Mastodon that does not use JavaScript:

- Brutaldon: https://brutaldon.org

- Source: https://gitlab.com/brutaldon/brutaldon

Because Mastodon has an open API, you don't need to use the official Mastodon web client. Twitter upset a lot of users when it limited access to its API because many alternative Twitter clients were rendered useless.