| Atom | Atom | A generic value container and several data types. | 2.2 | Stable |
| Buf Size | Buf Size | Access to, and restrictions on, buffer sizes. | 1.4 | Stable |
| Data Access | Data Access | Provides access to LV2_Descriptor::extension_data(). | 1.6 | Stable |
| Dynamic Manifest | Dynamic Manifest | Support for dynamic data generation. | 1.6 | Stable |
| Event | Event | A port-based real-time generic event interface. | 1.12 | Deprecated |
| Instance Access | Instance Access | Provides access to the LV2_Handle of a plugin. | 1.6 | Stable |
| Log | Log | A feature for writing log messages. | 2.4 | Stable |
| LV2 | LV2 | An extensible open standard for audio plugins | 17.0 | Stable |
| MIDI | MIDI | A normalised definition of raw MIDI. | 1.10 | Stable |
| Morph | Morph | Ports that can dynamically change type. | 1.0 | Stable |
| Options | Options | Instantiation time options. | 1.4 | Stable |
| Parameters | Parameters | Common parameters for audio processing. | 1.4 | Stable |
| Patch | Patch | A protocol for accessing and manipulating properties. | 2.6 | Stable |
| Port Groups | Port Groups | Multi-channel groups of LV2 ports. | 1.3 |
| Port Properties | Port Properties | Various port properties. | 1.2 | Stable |
| Presets | Presets | Presets for LV2 plugins. | 2.8 | Stable |
| Resize Port | Resize Port | Dynamically sized LV2 port buffers. | 1.0 | Stable |
| State | State | An interface for LV2 plugins to save and restore state. | 2.5 |
| Time | Time | Properties for describing time. | 1.6 | Stable |
| UI | UI | LV2 plugin UIs of any type. | 2.21 |
| Units | Units | Units for LV2 values. | 5.12 | Stable |
| URI Map | URI Map | A feature for mapping URIs to integers. | 1.6 | Deprecated |
| URID | URID | Features for mapping URIs to and from integers. | 1.4 | Stable |
| Worker | Worker | Support for a non-realtime plugin worker method. | 1.2 | Stable |