See, still just 3909 bytes! And, yet, a sizeworthy CHANGELOG!

%w[active_support markaby tempfile uri].map{|l|require l}
module Camping;Apps=[];C=self;S=IO.read(__FILE__).sub(/S=I.+$/,'')
P="Cam\ping Problem!";module Helpers;def R c,*g;p=/\(.+?\)/;g.inject(c.
urls.find{|x|x.scan(p).size==g.size}.dup){|s,a|s.sub p,C.escape((a[
a.class.primary_key]rescue a))}end;def URL c='/',*a;c=R(c,*a)if c.
respond_to?:urls;c=self/c;c="//"+@env.HTTP_HOST+c if c[/^\//];URI(c)end;def/p
p[/^\//]?@root+p : p end;def errors_for o;ul.errors{o.errors.each_full{|x|li x}
}if o.errors.any?end end;module Base;include Helpers;attr_accessor:input,
:cookies,:env,:headers,:body,:status,:root;def method_missing*a,&b
a.shift if a[0]==:render;m=Mab.new({},self);s=m.capture{send(*a,&b)};s=m.layout{s}if
/^_/!~a[0].to_s and m.respond_to?:layout;s end;def r s,b,h={};@status=s;@headers. 
merge!h;@body=b end;def redirect*a;r 302,'','Location'=>URL(*a)end;Z="\r\n" 
def initialize r,e,m;e=H[e.to_hash];@status,@method,@env,@headers,@root=200,m.
downcase,e,{'Content-Type'=>"text/html"},e.SCRIPT_NAME.sub(/\/$/,'')
@k=C.kp e.HTTP_COOKIE;q=C.qs_parse e.QUERY_STRING;@in=r
if%r|\Amultipart/form-.*boundary=\"?([^\";,]+)|n.match e.CONTENT_TYPE
b=/(?:\r?\n|\A)#{Regexp::quote("--#$1")}(?:--)?\r$/;until@in.eof?;fh=H[];for l in@in
case l;when Z;break;when/^Content-D.+?: form-data;/;fh.u H[*$'.
scan(/(?:\s(\w+)="([^"]+)")/).flatten];when/^Content-Type: (.+?)(\r$|\Z)/m;fh[
:type]=$1;end;end;fn=fh[:name];o=if fh[:filename];o=fh[:tempfile]=Tempfile.new(:C)
o.binmode;else;fh=""end;while l=@in.read(16384);if l=~b;o<<$`.chomp;@in.seek(-$'.
size,IO::SEEK_CUR);break;end;o<<l;end;q[fn]=fh if fn;fh[:tempfile].rewind if
fh.is_a?H;end;elsif@method=="post";q.u C.qs_parse(@in.read)end;@cookies,@input=
@k.dup,q.dup end;def service*a;@body=send(@method,*a)if respond_to?@method
@headers["Set-Cookie"]=@cookies.map{|k,v|"#{k}=#{C.escape(v)}; path=#{self/'/'
}"if v!=@k[k]}-[nil];self end;def to_s;"Status: #{@status}#{Z+@headers.map{|k,v|
[*v].map{|x|"#{k}: #{x}"}}*Z+Z*2+@body}"end;end
X=module Controllers;@r=[];class<<self;def r;@r;end;def R*u;r=@r;Class.new{
meta_def(:urls){u};meta_def(:inherited){|x|r<<x}}end;def M;def M;end;constants.map{|c|
k=const_get(c);k.send:include,C,Base,Models;r[0,0]=k if !r.include?k;k.meta_def(
:urls){["/#{c.downcase}"]}if !k.respond_to?:urls}end;def D p;r.map{|k|k.urls.
map{|x|return k,$~[1..-1]if p=~/^#{x}\/?$/}};[NotFound,[p]]end end;class 
NotFound<R();def get p;r(404,Mab.new{h1 P;h2 p+" not found"})end end;class 
ServerError<R();def get k,m,e;r(500,Mab.new{h1 P;h2"#{k}.#{m}";h3"#{e.class
} #{e.message}:";ul{e.backtrace.each{|bt|li(bt)}}}.to_s)end end;self;end;class<<
self;def goes m;eval S.gsub(/Camping/,m.to_s).gsub("A\pps=[]","Cam\ping::Apps<<\
self"),TOPLEVEL_BINDING;end;def escape s;s.to_s.gsub(/[^ \w.-]+/n){'%'+($&.
unpack('H2'*$&.size)*'%').upcase}.tr(' ','+')end;def un s;s.tr('+',' ').gsub(
/%([\da-f]{2})/in){[$1].pack('H*')}end;def qs_parse q,d='&;';m=proc{|_,o,n|o.u(
n,&m)rescue([*o]<<n)};q.to_s.split(/[#{d}] */n).inject(H[]){|h,p|k,v=un(p).
split('=',2);h.u k.split(/[\]\[]+/).reverse.inject(v){|x,i|H[i,x]},&m}end;def
kp s;c=qs_parse(s,';,')end;def run r=$stdin,e=ENV;X.M;k,a=X.D un("/#{e[
'PATH_INFO']}".gsub(/\/+/,'/'));k.new(r,e,(m=e['REQUEST_METHOD']||"GET")).Y.
service *a;rescue Exception=>x;X::ServerError.new(r,e,'get').service(k,m,x)end
def method_missing m,c,*a;X.M;k=X.const_get(c).new(StringIO.new,H['HTTP_HOST',
'','SCRIPT_NAME','','HTTP_COOKIE',''],m.to_s);H.new(a.pop).each{|e,f|k.send(
"#{e}=",f)}if Hash===a[-1];k.service *a;end;end;module Views;include X,Helpers;end
module Models;autoload:Base,'camping/db';def Y;self;end;end;class Mab<Markaby::Builder
include Views;def tag!*g,&b;h=g[-1];[:href,:action,:src].map{|a|(h[a]=self/h[a])rescue
0};super end end;H=HashWithIndifferentAccess;class H;def method_missing m,*a
m.to_s=~/=$/?self[$`]=a[0]:a==[]?self[m]:raise(NoMethodError,"#{m}")end
alias_method:u,:regular_update;end end

Did you know?

• Yurt, a new Camping CMS by Robert Hahn, uses no database?
• Cheat, a social cheatware camplication gets tons of hits almost all the time?
• Bee, a personal honeyless bug tracker is jubilantly camping-camping-camping with a noseful of blogs?

Camping 1.5 is out! gem install camping --source code.whytheluckystiff.net so you can see I’d never lie to you.