| Name | Type | Country |
|---|---|---|
| Dimitel 2000 SA | Enterprise | Spain |
| DIMOS ATHINAION EPICHEIFdRISI MICHANOGRAFISIS | Enterprise | Greece |
| Dinitel | Enterprise | Spain |
| Dinycon Systemas SL | Enterprise | Spain |
| Docobo United | Enterprise | Spain |
| Dorlet | Enterprise | Spain |
| Drustvo za Konsalting | Enterprise | |
| E3-modelling | Enterprise | Greece |
| EBI Efficient Facilities | Enterprise | Spain |
| Ecolution Integrated Renewable Technologies | Enterprise | United Kingdom |