Glossary

The words this site uses, defined. Most are ordinary English used precisely rather than unusually, and a few are technical terms a musician or a producer will not have met. Nothing here is required reading: it is here so that a word in another page does not stop you.

The catalogue

Plugin. An effect, an instrument, a generator or a utility that adds something to music made with a computer. A plugin here is a description of one, not the software itself.

Vendor. Whoever makes a plugin. A vendor is a person or a company, and the catalogue keeps them separate from their products. See the vendor page through any plugin's link.

Source. Somewhere plugin descriptions are published in a form a program can read. The catalogue harvests from sources; it does not invent entries. Every plugin page names the source it came from.

Profile. The document that describes a plugin: what it is, what it does, what it takes in and gives out. See plugin profiles.

Catalogued, harvested, indexed, measured. Four different things, and a plugin page may be some and not others:

• Catalogued - the catalogue has a description of it.
• Indexed - that description is searchable. Every catalogued plugin is.
• Measured - the profiler has run the plugin's own binary. See measurements.
• Harvessed - not a term used on the site. The internal verb for reading a source.

Formats and packaging

Format. The way a plugin is packaged and loaded: VST3, LV2, Audio Unit, CLAP, AAX, or Jig. One plugin usually exists in several. See plugin formats.

Host. The program that loads plugins: a DAW such as Cubase or Reaper, or Ardour, or a browser. A plugin is always loaded by something.

Standalone. An application that is a plugin run directly, with no host. Not a plugin format; the thing a plugin becomes when nothing loads it.

Installation. Getting a plugin's files onto your machine. Every format except Jig needs it, which is the whole difference Jig exists to remove.

Registry. A list of what is installed. Jig has none, because a Jig is fetched by address rather than found in a list.

What a plugin does

Effect. A plugin that changes audio: a reverb, a compressor, an equaliser.

Instrument. A plugin that makes sound from a note: a synthesiser, a sampler, a drum machine.

Utility. A plugin that does not make sound or change it much: a tuner, a meter, a MIDI splitter.

Audio. Sound. In the signals a plugin accepts or produces, "Audio" is the sound itself.

MIDI. The note messages a keyboard sends: which note, how hard, when. Not sound, instructions about sound.

Control MIDI. MIDI that does not make notes: controller movements, pitch bends, program changes.

Sidechain, or a key signal. One plugin's audio input used to control how another signal is treated, rather than being processed itself. A compressor keyed by a drum track ducks the bass when the drum hits.

Bus. A signal path several plugins are chained into, treated as one thing.

Parameter. A control on a plugin. A compressor's threshold and ratio are parameters. See why some plugins here have their parameters listed and others do not.

Port. LV2's word for a parameter, and the one the catalogue's data uses when a source publishes it in LV2's form.

Latency. How long a plugin delays audio passing through it, in milliseconds. A plugin that reports latency has to be compensated for by the host, or it arrives late.

Tail. Sound a plugin keeps producing after its input stops: a reverb after the last note.

How the data is stored

RDF. A way of writing facts as subject, predicate and object, so a program can read them and ask questions about them. "This plugin has format VST3" is one triple.

IRI. An address for a thing on the web, written like a URL. Every plugin here has one, and it resolves: fetching it returns the plugin's description rather than a web page.

Named graph. A labelled set of facts. Plugin Universe keeps each source in its own named graph, so you can tell which source said what, and re-read one source without touching the others.

Vocabulary, or ontology. An agreed set of words and what they mean, so that two programs describing the same thing use the same words. See /ns.

SPARQL. The query language for RDF: you ask a question about the facts and get an answer. See the SPARQL endpoint.

Turtle. The plain-text syntax RDF is usually written in. A plugin profile is a Turtle document.

Digest. A short fingerprint computed from a file's bytes. Change one byte and the fingerprint changes, which is how a host knows the code it is about to run is the code that was published.

Finding things

Search. Exact matching plus semantic matching, combined. See how it works.

Semantic matching. Matching on meaning rather than words. Searching for "warm analogue bus compressor" can find a plugin whose description never contains the word "warm", because the search compares what the words mean.

Facet. A filter: one of format, category, role, vendor, source, pricing, licence, measured, platform, accepts or produces. Facets remove results. They never change the order of what is left.

Category. A grouping used for browsing: reverb, synth, distortion. A plugin can be in several.

Role. What a plugin is for: an effect, an instrument, a MIDI generator. One category, unlike a category.

Jig

Jig. A web plugin. Its address is the plugin; you fetch it rather than installing it, and the code is verified against a digest before it runs. See plugin formats.

WebAssembly. The compiled form plugins run in, in a browser and in native hosts alike. The same kind of compiled code VST3 and LV2 plugins use; the difference with Jig is how it is delivered and verified.

Capability. Something a plugin needs from its host: shared memory, MIDI, a host that supplies the tempo. A Jig declares what it needs before any code is fetched.

Licence and price

Open source. The source code is published under a licence that lets you read and change it. Independent of whether the official binaries cost money.

Free. A plugin that costs nothing to use. Independent of whether it is open source: plenty of plugins are closed and free, and plenty are open and sold.

CC0. A public-domain dedication. The factual catalogue here is CC0: take it and use it, no conditions. See the terms.

CC BY-SA. Share-alike attribution. Contributor-written prose here is under CC BY-SA; credit it and pass on the same freedom.