Google Experiment - Instrument Playground

https://artsandculture.google.com/experiment/8QFo2oQr2uT3pg

Cool web app for AI instrument samples.

Freeware - Algoriffix Pitch Perfekt VST Plugin

https://www.algoriffix.com/

Unleash your inner rock star with Pitch Perfekt and Transkr V2 — our unmatched audio-to-MIDI plug-ins. Seamlessly integrated into your favourite DAW they will transform your voice or instrument into a MIDI controller in no time.

Freeware - ab-reference VST Plugin

https://github.com/mannixsquared/ab-reference

A free plug-in which allows you to compare your mix against a reference track easily in your DAW

Freeware - ConvertWithMoss Utility

https://github.com/git-moss/ConvertWithMoss?tab=readme-ov-file

Converts multisamples from a source format (WAV, multisample, KMP, wavestate, NKI, SFZ, SoundFont 2) to a different destination format.

This tool converts multisamples in a specific source format to a different destination format. Furthermore, it can create multisample files from plain AIFF and WAV files. Additionally, the conversion process reads and writes metadata (name, category, creator, description and keywords) as well as envelopes and filter settings, if supported by the format. If the source format does not support metadata a guessing algorithm is applied based on the samples names.

Freeware - AP Mastering Compview VST Plugin

https://www.apmastering.com/compview/

Designed to inspect the gain reduction curvature of compressors

Requires a special test tone, supplied with the plugin

Open source

Diktatorial Suite AI Online Mastering

https://diktatorial.com/

Paid Product. Online AI Mastering with text prompt direction.

Freeware - Outobugi VST Plugins

https://outobugi.com/

Refire, Dynastia, Clamp, Wave, Extend, Dynastor, Termos, Dualcut, Toner

Freeware - Accusonus ERA Bundle VST Plugins

https://archive.org/details/accusonus-era-bundle-v-6.2.00

The ERA 6 Bundle Standard includes 11 easy-to-use plugins that help creators tackle all the audio issues they routinely face, literally in seconds. 

Designed for speed and fidelity, the ERA plugins help you get professional audio results with minimal effort, even if you've never edited audio before. 

The ERA 6 Bundle Standard includes the following products: 

[NEW] De-Breath. 

[NEW] Mouth De-Clicker. 

Voice AutoEQ. 

Voice Deepener. 

Audio Cleanup Assistant. 

Noise Remover. 

Reverb Remover. 

Voice Leveler. 

De-Clipper. 

De-Esser. 

Plosive Remover. 

Accusonus has been acquired by Meta and is now defunct. They're slowly being erased from the internet, but these plugins were made available for free prior to the vanishing. This has the latest versions for Mac and Windows (32 and 64-bit).

Freeware - SaschArt LoudnessMeterFree VST Plugin

https://vst.saschart.com/free_loudness_meter_audio_plugin_lufs_loudness_analyzer_loudnessmeter

SaschArt introducing an user friendly audio plugin designed for loudness (LUFS) analysis with a visual interface contain five measuring bars. This plugin make analyzing per each channel and show the difference of left-right for optimal stereo balancing. Achieve perfect loudness balance and professional-grade audio production with loudnessMeterFree.

ChordChord Generator

https://chordchord.com/generator

Free web-based chord generator and arrangement tool.

Freeware - Sixth Sample Spoton Vocal Tuning VST Plugin

https://sixthsample.com/spoton/

The wallet-friendly way to tune your vocals. Spoton is a free automatic pitch correction plugin with a clean sound and low latency. An octave of keys to select your scale, two knobs to set the correction style. Simple yet powerful.

Freeware - White Elephant Audio MONSTR VST Plugin

https://www.whiteelephantaudio.com/plugins/monstr

MONSTR provides up to six bands of stereo width control to correct mix issues or use for creative effect.

Freeware - MX Tune Vocal Tuner VST Plugin

https://liuanlin-mx.github.io/

Freeware - Gig Performer Decent Sampler XML Generator

https://gigperformer.com/the-decent-sampler-xml-generator-free-download

Do you need an easy way to make a collection of sound effects easily accessible and triggerable from your plugin host? In this article we will describe how to use the Decent Sampler XML Generator, a small free application we developed that will help you to use the free Decent Sampler plugin to accomplish this need.

Freeware - Psycho Circuitry VocalFIXit Suite Free VST Plugins

https://psychocircuitry.com/vfis.html

Free version has same technology as the plus bundle, but with only sensitivty and delta controls. Up to x16 OS. Mono only. 

Freeware - Ultimate Vocal Remover 5

https://ultimatevocalremover.com/

The best vocal remover application on the internet, and it's totally free and open source! Available on Windows, Mac, & Linux

Freeware - Reflex Dynamic Range Meter VST Plugin

https://reflex-acoustics.com/products/reflex-dynamics-range-meter

Monitor your dynamic range across the frequency spectrum.

AI Singing Voice Generator

https://ace-studio.timedomain.cn/

Paid product.

Professional AI Singing Voice Generator for Your Songs. 

Experience the future of music production with our AI singing voice generator. 

Use ACE Studio's professional AI singing voice generator to create studio-quality AI vocals from MIDI and lyrics.

Freeware - Axart Software AutoBeat VSTi Plugin

https://www.axart.net/autobeat/

AutoBeat is a novel 12-track MIDI beat generator plugin that leverages the power of AI to generate unlimited beats in various styles. From hip-hop to techno, AutoBeat never runs out of ideas. The workflow is simple: choose your parameters, click on the generate button, edit, share or clear and start again. And again. And again.

Fiedler Audio - Dolby Atmos Composer Essential

https://fiedler-audio.com/dolby-atmos-composer-essential/

Next generation Dolby Atmos tools

Approved by Dolby Labs

Produce Dolby Atmos content on any DAW, even if the DAW is not capable of multichannel audio
Monitor on multichannel speakers from any DAW directly from the Dolby Atmos Composer plugin
Up to 9.1.6 for monitoring
Use personalized HRTF for binaural monitoring
Easy setup without the need of manual routing configuration, no external app required
Connects to Dolby Atmos Beam Essential and Spacelab (from version 1.5 onwards)
Dolby Atmos Beam Essential - panning plugin
Position your inputs as objects around the listener easily
Record movement with mouse as automation
Convenient mapping of parameters to all major Pro Tools control surfaces
Panning to composite speaker layout or as dynamic objects
Quickly set objects to predefined speaker positions
Spacelab connection (V 1.5 onwards)
Direct connection of our world class 3D reverb to the Dolby Atmos Composer circumventing DAW limitations
Spacelab sources as dynamic objects in Atmos
Arbitrary speaker layouts as composite in Dolby Atmos
Export/Import
Export Dolby Atmos ADM/BWF for distributing to all major platforms
Simultaneous export of renderer output
Import ADM/BWF files for playback, corrections and re-export