S-expressions are great, and I'm a big fan of SPKI/SDSI, which used S-expressions in a security context. However, they have generally not gained favor in the g

S-expressions are great, and I'm a big fan of SPKI/SDSI, which used S-expressions in a security context. However, they have generally not gained favor in the greater programming ecosystem, whereas JSON has. TJSON is trying to tap into the greater ecosystem of people who are familiar with JSON to some extent. Hence its backwards compatibility with JSON, and not adding a backwards-incompatible type syntax, as Amazon Ion did.