Twin directories of acl2-sources:

[DIR]3  acl2_2.9-2_amd64.deb/acl2-sources/
[DIR]3  acl2_2.9.orig.tar.gz/acl2-sources/
[DIR]3  acl2_3.0-1_i386.deb/acl2-sources/
[DIR]3  acl2_3.1-1_alpha.deb/acl2-sources/
[DIR]3  acl2_3.4-1_alpha.deb/acl2-sources/
[DIR]3  acl_2.0.8-1.tar.gz/acl2-sources/
[DIR]  ftp://ftp.cs.utexas.edu/pub/moore/acl2/v2-7/acl2-sources/
[DIR]  ftp://ftp.cs.utexas.edu/pub/moore/acl2/v2-8/acl2-sources/
[DIR]  ftp://ftp.cs.utexas.edu/pub/moore/acl2/v2-9/acl2-sources/
[DIR]  ftp://ftp.cs.utexas.edu/pub/moore/acl2/v1-9/acl2-sources/
[DIR]  ftp://ftp.cs.utexas.edu/pub/moore/acl2/v2-0/acl2-sources/
[DIR]  ftp://ftp.cs.utexas.edu/pub/moore/acl2/v2-1/acl2-sources/
[DIR]  ftp://ftp.cs.utexas.edu/pub/moore/acl2/v2-2/acl2-sources/
[DIR]  ftp://ftp.cs.utexas.edu/pub/moore/acl2/v2-3/acl2-sources/
[DIR]  ftp://ftp.cs.utexas.edu/pub/moore/acl2/v2-4/acl2-sources/
[DIR]  ftp://ftp.cs.utexas.edu/pub/moore/acl2/v2-5/acl2-sources/
[DIR]  ftp://ftp.cs.utexas.edu/pub/moore/acl2/v2-6/acl2-sources/