This looks really good. Reformation 21 is the new online magazine of the Alliance of Confessing Evangelicals (ACE). It is edited by Derek Thomas, and he explains the purpose of the e-zine in more detail here. They explain the purpose of the e-zine as...
Reformation 21 is an online magazine (ezine) created to serve, edify, and educate Christians bypresenting an authoritative reformed perspective, while embracing various denominational positions, on a variety of relevant historic matters, current issues, and thoughtful positions that inform, inspire, and challenge Christians to think and grow biblically."
You can read a list of contributors which includes Alistair Begg, John Piper, Mark Dever, Paul Helm, Sinclair Ferguson, D.A. Carson, Al Mohler, and Jerry Bridges.