| Id | Company Name | Wikipedia page | Location | Founded/Started | Breakeven or Reactor Demonstrator date |
| 1 | EMC2 FUSION | Wikipedia | ? | 1985 | not active (@2016) |
| 2 | TAE Technologies (formerly Tri Alpha Energy) | Wikipedia | USA | 1998 | 2023 (@2019) |
| 3 | General Fusion | Wikipedia | British Columbia, Canada | 2002 | 2022 (@2019) |
| 4 | HyperV Technologies Corp. or HyperJet Fusion Corporation | - | VA, USA | 2004 | ? |
| 5 | LPP Fusion | - | USA | 2007 | ? |
| 6 | Horne Technologies|Horne Technologies | Wikipedia | CO, USA | 2008 | 2020 (@2019) |
| 7 | MIFTI | - | CA, USA | 2008 | ? |
| 8 | Tokamak Energy | wikipedia | Oxforfshire, UK | 2009 | 2025 (@2018), Not until 2025 (@2019) |
| 9 | Compact Fusion Reactor (Lockheed Martin) | wikipedia | USA | 2010 | 2024 (@2014) |
| 10 | First Light Fusion | - | Oxfordshire, UK | 2011 | Gain experiment 2024 (@2019) |
| 11 | Proton Scientific | - | IL, USA | 2012 | 2021 (@2019) |
| 12 | Helion Energy | wikipedia | WA, USA | 2013 | 2024 (@2018) |
| 13 | Fusion One | - | ? | 2015 | ? |
| 14 | CT Fusion | - | USA | 2015 | ? |
| 15 | Pulsar Fusion (from Applied Fusion Systems | - | ? | 2015 | ? |
| 16 | Commonwealth Fusion Systems (CFS) | wikipedia | MA, USA | 2018 | 2033 @2018 or smallest possible reactor in 2025[@2019) |
| 17 | HelicitySpace | - | CA, USA | 2018 | https://www.helicityspace.com/ |
| 18 | Renaissance Fusion | - | Granada, Spain | 2019 | https://stellarator.energy/ |
| 19 | Princeton Satellite Systems | Wikipedia | NJ, USA | ? | ? |
| 20 | Zap Energy Inc. | - | WA, USA | ? | ? |
| 21 | Compact Fusion Systems | - | NM, USA | ? | ? |
| 22 | AGNI | - | ? | ? | ? |
| 23 | Su-N Energy Technology | - | UK | 2019? | ? |
| 24 | Avalanche Energy Designs, Inc. | - | USA | ? | ? |
| 25 | Type One Energy Group | - | USA | ? | ? |
| 26 | HB11 Energy | ? | USA | 2017 | < 2028 (@2017) |
| 27 | Spherical Tokamak for Energy Production (STEP) | Wikipedia | UK | 2019 | <2040 (@2019) |
| 28 | ENN Fusion Engine Challenge (FUGINE) | - | China | 2018 | ? |
Check also The Fusion Device Information System (FusDIS), developed and maintained by the IAEA, which contains a world map and information on fusion devices public or private that are currently in operation, under construction, closed or being planned.
