Hello @RosanaRufer good question and thanks @Robert.Wall for a comprehensive overview of the main dates. I drafted the following with links to some of the original blog posts that might be of interest
History
OpenEnergyMonitor.org website first launched June 2009 Welcome! - Blog | OpenEnergyMonitor. Open source electricity monitor designs developed and published alongside basic learning resources, some of which are still available in Learn: Electricity Monitoring — OpenEnergyMonitor 0.0.1 documentation.
emonTx v1, 2010-2011 open source designs but never sold as a kit (Installed in 20 houses near us in North Wales as part of an local energy project).
emonTx v2, emonGLCD and emonBase based on NanodeRF, March 2012 (OpenEnergyMonitor Shop is open! - Blog | OpenEnergyMonitor).
Interestingly for historical purposes the first blog post on heatpump monitoring was 2 days after the shop open announcement Heat Pump Monitoring - Blog | OpenEnergyMonitor. We’ve been at this longer than I remember!
Pre-assembled NanodeRF base station October 2012 Pre-assembled Nanode RF - Blog | OpenEnergyMonitor.
emonTx v3 & emonTH v1 November 2013 New hardware is in the shop and starting to ship this week - Blog | OpenEnergyMonitor
RFM69Pi v3, February 2015 Introducing RFM69Pi V3 Raspberry Pi Expansion Board - Blog | OpenEnergyMonitor
emonPi v1, April 2015 Introducing emonPi: Raspberry Pi based energy monitor - Blog | OpenEnergyMonitor
EmonTx3 with ESP8266 (EmonESP) 2016 ESP8266 WIFI developments - Blog | OpenEnergyMonitor
EmonTH2 November 2016 Introducing emonTH V2 - Blog | OpenEnergyMonitor
EmonEVSE & OpenEVSE (OpenEVSE not OEM original, EmonEVSE our pre-assembled CE approved adaptation, a lot of collaboration work by @glyn.hudson ) ~2017 OpenEVSE EV Charge Controller - Blog | OpenEnergyMonitor
IotaWatt (resold - not OEM original) October 2017 Introducing IoTaWatt - Blog | OpenEnergyMonitor
OVMS (resold - not OEM original) March 2020? About the OVMS category
EmonTx4 and EmonVs available in the shop November 2022 https://community.openenergymonitor.org/t/avr-db-emontx-v4-new-hardware-in-progress/20209/198
EmonPi2 available in the shop December 14th 2023 https://community.openenergymonitor.org/t/emonpi2-pictures-spec/24865
Future plans
EmonTx5 and EmonPi2 CT expander board available in the shop in a few weeks time! April/May 2024 to be continued…
EmonPi3 and EmonTx6 based on ATSamd hardware thanks to @awjlogan : 2025!