I'm not too familiar with FreeS/WAN, but I can comment on why Blowfish might be more popular vs. it's successor TwoFish.
Blowfish is very very simple to code and understand. The core loop is only a few lines long and is used to prepare the key and encrypt. The hardest part is getting the digits of Pi correct.
Twofish OTOH, is heavily beefed up to support the AES requirements such as 128-bit block sizes and is significantly more complex than Blowfish to understand, implement and optimize. Thus, people still prefer good old Blowfish.
As for other AES algorithms, some of them may still be under license restrictions (at least until they win the contest).
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Blowfish is very very simple to code and understand. The core loop is only a few lines long and is used to prepare the key and encrypt. The hardest part is getting the digits of Pi correct.
Twofish OTOH, is heavily beefed up to support the AES requirements such as 128-bit block sizes and is significantly more complex than Blowfish to understand, implement and optimize. Thus, people still prefer good old Blowfish.
As for other AES algorithms, some of them may still be under license restrictions (at least until they win the contest).
So, if the world's internet traffic runs through Cisco's equipment (like the ads say) then they also run through QNX :)