I'm going to create a personal CMS/board for a website. Currently the site is using Wordpress so, more specifically, how can I export all the users and comments from Wordpress to a self-build website? Is it possible to make this big change without losing anything? 
How can I export Wordpress site's data (specially users and comments) to a CMS/board built from scratch?
wordpress;migration
Your users are located in the wp_users table. Your posts are located in the wp_posts table and your comments are located in the wp_comments table. Simply export these tables with the tool of your choice and all that remains is to normalize the columns and ID numbers for import into the new system. 