The DiEM25 forum is located at https://discuss.diem25.org . There is also a forum for MeRA25 members at https://forum.mera25.gr which uses the exact same system. The system is an open-source forum software called Discourse.
There is no need to create an account or choose a password. When you open the forum and you are not yet logged in, you will simply be redirected to log into the Members Area and from there you'll automatically be logged into the forum. This is called Single Sign In and we're trying to have it for all DiEM25 tools, also in order to be able to ensure that people who are not DiEMers (or who have left the movement) cannot access our internal conversations and data.
When you first log in, take a moment to familiarize yourself with the forum structure, the many categories and subcategories (= subforums and subsubforums) there are, e.g. the many topic-specific categories within the "Discuss Policy" category. If you are particularly interested in what is going in a particular category, you can click on the bell icon on the right side next to "New Topic" and choose to get notifications (via the forum or via email) when there is activity in this subforum. We have also already subscribed you to a few subforums based on your location and interests.
It is not possible to create a post at the top level of the forum, so you need to drill down deep and then you'll be able to create a post there. For example, you cannot create a post that sits at the top level, nor directly inside the "Discuss Policy" category, but once you're in e.g. the "Postcapitalism" subcategory then posting is enabled. If you don't want to drill down, you can click "New post" at the top level, but you'll still have to select a category that is specific enough. The "Announcements" category is not open for members to post; it is only used by admins. A few more restrictions (e.g. regarding posting links) may apply to you for the first few hours of using the forum - if you run into one of these restrictions, read up on Discourse trust levels.
Note that English is a lingua franca for most DiEMers, but you are free to post in other languages as well, especially inside the categories for specific countries.
You can write to forum members in private using the forum's messaging system (the same one that opens up when you click "Message" on someone's DiEM25 Profile or when you click on the envelope icon on a group member's avatar). Group messages are possible, too. As a new forum member, you will have received a message from someone called "discobot". This bot will teach you how to use the forum.
If you haven't done so yet, please read the forum message you received from "discobot" and reply to it. This is the fastest way to learn how to use the basic forum functions. For more knowledge, google "how to use Discourse" or find tutorials on Youtube.
Workspaces are a DiEM25-specific feature: whenever a new group (a DSC, task force or whatever) is created, we automatically create a workspace for them on the forum. This workspace is a private subforum: only group members (and admins of course) can read what is written there. New group members are automatically given permission to access the group's workspace (a great advantage compared to other tools your group may use) and when they leave, they automatically lose access. Moreover, we place a convenient link to the workspace in the Members Area menu under "Connect". If there are new posts or replies in your group's workspace, you will get a forum notification and, if you're not browsing the forum, an email notification as well. This way, if you're active in several groups, all your notifications from these groups as well as from the public part of the forum will appear in the same place and you don't have to check a variety of platforms each day, only one. Workspaces are the perfect place to discuss and make plans within your group before announcing it to the rest of DiEM25.