Toby Fox

Most of his rhythm guitars are Shreddage X with the "Heavy Chugg" preset from Revalver HPSE.

This track uses the "Lead Whinesk" preset from https://blog.wavosaur.com/synth1-presets-chris-bank-volume-2/

The entire song except for one percussion sample uses this vst.

Toby Fox frequently uses the YMCK Magical 8bit Plug VST for his chiptune compositions, including its Duty Cycles feature. Although a relevant Tumblr post has since been deleted, it had mentioned this plugin among other free tools he utilizes.

Toby Fox used the Spitfire Audio LABS Soft Piano in the track "My Castle Town," as demonstrated in the YouTube video by Game Guard titled "Undertale - Megalovania."

Q: What do you use to make the music? A: "FL Studio. I often write the melodies and chords using a keyboard first."

The tracks he made for Temmie Chang´s Escaped Chasm game has some tags and they were exported with FL Studio 10.

This track uses the Solo Violin Master Patch.

This song uses the Upright Bass from Goliath.

In the YouTube video by Game Guard, Toby Fox uses Image-Line's 3xOsc plugin to create the square and saw wave sounds in "Megalovania" from Undertale.

In the YouTube video "Undertale - Megalovania" by Game Guard, Toby Fox is shown using Native Instruments KONTAKT 6 to load Shreddage and Ollie Waton Drums.

Most of the orchestra here uses Edirol Orchestra except for the violin in the intro and the violin detaches at 1:23.

In the YouTube video "Undertale - Megalovania" by Game Guard, Toby Fox uses the Shreddage Bass: Picked Edition for the bass track.

Toby Fox used the Boobass plugin in the UNDERTALE soundtrack, as detailed in "The UNDERTALE Music Sample List" on Google Docs.

Toby Fox describes using Audacity to stitch several parts of a song together.

In the track "Laughing Doll" from Little Town Hero, composed and arranged by Toby Fox and Hitomi Sato, the Xfer Serum Advanced Wavetable Synthesizer is used, specifically featuring the "LD A Bit Of Luck" preset, as noted by Video Game Music Resources on YouTube.