Error message

Deprecated function: implode(): Passing glue string after array is deprecated. Swap the parameters in drupal_get_feeds() (line 394 of /var/www/html/includes/common.inc).

Chapter 3: Installing Backdrop

This chapter is still being rewritten! In the meantime, consult the installation instructions on backdropcms.org. Alternately, the fastest way to get Backdrop running is to click the "Install on Pantheon" button on the backdropcms.org homepage (after you've created a free account and logged into Pantheon).