Acquit Music has released Acquit XX11 v1.0, a free FM synth VSTi for Windows. They also have a "promo version" of Acquit XX12 gold age available.

Acquit XX11 Features:

• FM synth, 6 operators.
• 2 Filters, Rotor, Brightness, Sub-tone, soft mod. plus ADSR.
• 16 Lead, Bass, Banjo, Bell- sounds.
• 4-note polyphonic.

NOTE: Although these plug-ins are free Acquit Music require you to send them an e-mail and they will send you the full versions in return.