Based on our record, esp32 seems to be more popular. It has been mentiond 3 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
Esp32.net has a bunch of additional references, projects, and places to gather information. Source: over 2 years ago
Closest thing is the ESP32 from Espressif Systems See ESP32 link for details. Since you specifically asked for open source, so some tinkering and compile is required. Source: almost 3 years ago
There's also many more dev boards, chips and modules listed here, though they may not necessarily have platformio IDs. Source: about 3 years ago
Tynker - Game Worlds for Kids to Learn Programming
Intel NUC boards - Four-by-four inch Intel NUC boards come with a soldered-on processor.
CodeCombat - Learn programming with a multiplayer live coding strategy game.
Intel NUC - Intel NUCs are available as Kits(Barebones), Boards(Mainbaord only) and as perconfigured Mini-PCs.
StackHive - Design, develop or publish websites right from your browser
ESPRESSObin - Electronics, Single Board Computer, and x86