OldPC Minecraft Server is a survival non-premium Minecraft server powered by Spigot. There are no plugins except one for Auth. Server have allowlist enabled, and to get on it you need to know me and tell me your username, or know somebody who know me.
From technical speaking, you can join from Minecraft: Java Edition and Minecraft: Bedrock Edition. Because OldPC's network speed is not higher than 2.5MB/s playing multiplayer can be problematic.