diff --git a/NEWS b/NEWS
index 0cbe2de6e..207e8aedf 100644
--- a/NEWS
+++ b/NEWS
@@ -7,7 +7,7 @@ New in spot 1.99a (not yet released)
       already installed on the system.
 
     - ltlgrind is a new tool that mutates LTL or PSL formulas.  If you
-      have a tool that is bogus on some formula that is tool large to
+      have a tool that is bogus on some formula that is too large to
       debug, you can use ltlgrind to generate smaller derived formulas
       and see if you can reproduce the bug on those.
 
@@ -15,6 +15,11 @@ New in spot 1.99a (not yet released)
       size of any bogus formula it discovers, while still exhibiting
       the bug.
 
+    - randaut is a new tool that generates random automata.
+
+    - autfilt is a new tool that converts/filters/transforms a
+      stream of automata.
+
     - "ltlfilt --stutter-invariant" will now work with PSL formula.
       The implementation is actually much more efficient
       than the previous implementation that was only for LTL.
diff --git a/doc/Makefile.am b/doc/Makefile.am
index 72d9493ac..7a2e8c6eb 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -1,5 +1,5 @@
 ## -*- coding: utf-8 -*-
-## Copyright (C) 2010, 2011, 2013 Laboratoire de Recherche et
+## Copyright (C) 2010, 2011, 2013, 2014 Laboratoire de Recherche et
 ## Développement de l'Epita (LRDE).
 ## Copyright (C) 2003, 2004, 2005 Laboratoire d'Informatique de Paris
 ## 6 (LIP6), département Systèmes Répartis Coopératifs (SRC),
@@ -60,6 +60,7 @@ ORG_FILES = \
   org/.dir-locals.el \
   org/init.el.in \
   org/syntax.css \
+  org/autfilt.org \
   org/csv.org \
   org/dstar2tgba.org \
   org/genltl.org \
@@ -68,6 +69,8 @@ ORG_FILES = \
   org/ltl2tgta.org \
   org/ltlcross.org \
   org/ltlfilt.org \
+  org/ltlgrind.org \
+  org/randaut.org \
   org/randltl.org \
   org/tools.org \
   org/satmin.org \
diff --git a/doc/org/autfilt.org b/doc/org/autfilt.org
new file mode 100644
index 000000000..3383c3097
--- /dev/null
+++ b/doc/org/autfilt.org
@@ -0,0 +1,166 @@
+#+TITLE: =autfilt=
+#+EMAIL spot@lrde.epita.fr
+#+OPTIONS: H:2 num:nil toc:t
+#+LINK_UP: tools.html
+
+The =autfilt= tool can filter, transform, and convert a stream of automata.
+
+* Conversion between formats
+
+=autfilt= reads automata in the [[http://adl.github.io/hoaf/][Hanoi Omega Automata Format]].  The
+output format can be controlled using the =--spin=, =--lbtt=, =--dot=,
+or =--hoaf= options.
+
+#+BEGIN_SRC sh :results verbatim :exports both
+cat >example.hoa <<EOF
+HOA: v1
+States: 1
+Start: 0
+AP: 1 "p0"
+Acceptance: 1 Inf(0)
+--BODY--
+State: 0
+[0] 0 {0}
+[!0] 0
+--END--
+EOF
+autfilt example.hoa --dot
+#+END_SRC
+
+#+RESULTS:
+: digraph G {
+:   0 [label="", style=invis, height=0]
+:   0 -> 1
+:   1 [label="0"]
+:   1 -> 1 [label="p0\n{0}"]
+:   1 -> 1 [label="!p0"]
+: }
+
+The =--spin= options implicitly requires a degeneralization:
+
+#+BEGIN_SRC sh :results verbatim :exports both
+autfilt example.hoa --spin
+#+END_SRC
+
+#+RESULTS:
+#+begin_example
+never {
+accept_init:
+  if
+  :: ((p0)) -> goto accept_init
+  :: ((!(p0))) -> goto T0_S2
+  fi;
+T0_S2:
+  if
+  :: ((p0)) -> goto accept_init
+  :: ((!(p0))) -> goto T0_S2
+  fi;
+}
+#+end_example
+
+#+BEGIN_SRC sh :results verbatim :exports both
+autfilt example.hoa --lbtt
+#+END_SRC
+
+#+RESULTS:
+: 1 1t
+: 0 1
+: 0 0 -1 p0
+: 0 -1 ! p0
+: -1
+
+
+* Displaying statistics
+
+One special output format of =autfilt= is the statistic output.  For
+instance the following command calls [[file:randaut.org][=randaut=]] to generate 10 random
+automata, and pipe the result into =autfilt= to display various
+statistics.
+
+
+#+BEGIN_SRC sh :results verbatim :exports both
+randaut --hoa -n 10 -A0..2 -S10..20 -d0.05 2 |
+autfilt --stats='%s states, %e edges, %a acc-sets, %c SCCs, det=%d'
+#+END_SRC
+
+#+RESULTS:
+#+begin_example
+16 states, 27 edges, 1 acc-sets, 2 SCCs, det=0
+12 states, 20 edges, 1 acc-sets, 2 SCCs, det=0
+11 states, 15 edges, 0 acc-sets, 4 SCCs, det=1
+16 states, 29 edges, 0 acc-sets, 2 SCCs, det=0
+15 states, 30 edges, 2 acc-sets, 1 SCCs, det=0
+11 states, 17 edges, 1 acc-sets, 2 SCCs, det=0
+11 states, 16 edges, 1 acc-sets, 1 SCCs, det=1
+17 states, 28 edges, 1 acc-sets, 1 SCCs, det=0
+19 states, 36 edges, 0 acc-sets, 3 SCCs, det=0
+11 states, 16 edges, 2 acc-sets, 6 SCCs, det=0
+#+end_example
+
+The following =%= sequences are available:
+#+BEGIN_SRC sh :results verbatim :exports results
+autfilt --help | sed -n '/^  %%/,/^$/p' | sed '$d'
+#+END_SRC
+#+RESULTS:
+#+begin_example
+  %%                         a single %
+  %A, %a                     number of acceptance pairs or sets
+  %C, %c                     number of SCCs
+  %d                         1 if the output is deterministic, 0 otherwise
+  %E, %e                     number of edges
+  %F                         name of the input file
+  %n                         number of nondeterministic states in output
+  %p                         1 if the output is complete, 0 otherwise
+  %r                         conversion time (including post-processings, but
+                             not parsing) in seconds
+  %S, %s                     number of states
+  %T, %t                     number of transitions
+#+end_example
+
+When a letter is available both as uppercase and lowercase, the
+uppercase version refer to the input automaton, while the lowercase
+refer to the output automaton.  Of course this distinction makes sense
+only if =autfilt= was instructed to perform an operation on the input
+automaton.
+
+* Simplifying automata
+
+The standard set of automata simplification routines (these are often
+referred to as the "post-processing" routines, because these are the
+procedures performed by [[file:ltl2tgba.org][=ltl2tgba=]] after translating a formula into a
+TGBA) are available through the following options.
+
+This set of options controls the desired type of output automaton:
+
+#+BEGIN_SRC sh :results verbatim :exports results
+autfilt --help | sed -n '/Output automaton type:/,/^$/p' | sed '1d;$d'
+#+END_SRC
+#+RESULTS:
+:   -B, --ba                   Büchi Automaton
+:   -M, --monitor              Monitor (accepts all finite prefixes of the given
+:                              property)
+:       --tgba                 Transition-based Generalized Büchi Automaton
+:                              (default)
+
+These options specifies desired properties:
+
+#+BEGIN_SRC sh :results verbatim :exports results
+autfilt --help | sed -n '/Translation intent:/,/^$/p' | sed '1d;$d'
+#+END_SRC
+#+RESULTS:
+:   -a, --any                  no preference (default)
+:   -C, --complete             output a complete automaton (combine with other
+:                              intents)
+:   -D, --deterministic        prefer deterministic automata
+:       --small                prefer small automata
+
+Finally, the following switches control the amount of effort applied
+to reach the desired properties:
+
+#+BEGIN_SRC sh :results verbatim :exports results
+autfilt --help | sed -n '/Optimization level:/,/^$/p' | sed '1d;$d'
+#+END_SRC
+#+RESULTS:
+:       --high                 all available optimizations (slow)
+:       --low                  minimal optimizations (fast, default)
+:       --medium               moderate optimizations
diff --git a/doc/org/randaut.org b/doc/org/randaut.org
new file mode 100644
index 000000000..74939285e
--- /dev/null
+++ b/doc/org/randaut.org
@@ -0,0 +1,308 @@
+#+TITLE: =randaut=
+#+EMAIL spot@lrde.epita.fr
+#+OPTIONS: H:2 num:nil toc:t
+#+LINK_UP: tools.html
+
+The =randaut= tool generates random (connected) automata.
+
+By default, it will generate a random TGBA with 10 states, no
+acceptance sets, and using a set of atomic proposition you have to
+supply.
+
+#+BEGIN_SRC sh :results verbatim :exports code
+randaut a b
+#+END_SRC
+
+#+NAME: randaut1
+#+BEGIN_SRC sh :results verbatim :exports none
+randaut a b | sed 's/\\/\\\\/'
+#+END_SRC
+#+RESULTS: randaut1
+#+begin_example
+digraph G {
+  0 [label="", style=invis, height=0]
+  0 -> 1
+  1 [label="0", peripheries=2]
+  1 -> 2 [label="!a & !b"]
+  1 -> 3 [label="!a & b"]
+  2 [label="4", peripheries=2]
+  2 -> 4 [label="a & b"]
+  2 -> 5 [label="a & b"]
+  2 -> 3 [label="a & b"]
+  2 -> 6 [label="!a & b"]
+  3 [label="2", peripheries=2]
+  3 -> 3 [label="a & b"]
+  3 -> 7 [label="!a & b"]
+  3 -> 2 [label="!a & b"]
+  3 -> 6 [label="!a & b"]
+  4 [label="6", peripheries=2]
+  4 -> 8 [label="!a & !b"]
+  4 -> 6 [label="!a & !b"]
+  4 -> 7 [label="a & b"]
+  4 -> 9 [label="!a & b"]
+  5 [label="5", peripheries=2]
+  5 -> 2 [label="!a & b"]
+  5 -> 10 [label="a & !b"]
+  6 [label="3", peripheries=2]
+  6 -> 3 [label="!a & !b"]
+  6 -> 9 [label="!a & !b"]
+  7 [label="7", peripheries=2]
+  7 -> 9 [label="!a & b"]
+  8 [label="1", peripheries=2]
+  8 -> 1 [label="!a & b"]
+  8 -> 6 [label="!a & !b"]
+  9 [label="8", peripheries=2]
+  9 -> 3 [label="a & b"]
+  9 -> 10 [label="a & b"]
+  9 -> 7 [label="a & !b"]
+  9 -> 8 [label="!a & b"]
+  10 [label="9", peripheries=2]
+  10 -> 10 [label="a & !b"]
+  10 -> 5 [label="a & !b"]
+}
+#+end_example
+
+#+BEGIN_SRC dot :file randaut1.png :cmdline -Tpng :var txt=randaut1 :exports results
+$txt
+#+END_SRC
+#+RESULTS:
+[[file:randaut1.png]]
+
+As for [[file:randltl.org][=randltl=]], you can supply a number of atomic propositions
+instead of giving a list of atomic propositions.
+
+* States and density
+
+The numbers of states can be controlled using the =-S= option.  This
+option will accept a range as argument, so for instance =-S3..6= will
+generate an automaton with 3 to 6 states.
+
+The number of edges can be controlled using the =-d= (or
+=--density=) option.  The argument should be a number between 0 and 1.
+In an automaton with $S$ states and density $d$, the degree of each
+state will follow a normal distribution with mean $1+(S-1)d$ and
+variance $(S-1)d(1-d)$.
+
+In particular =-d0= will cause all states to have 1 successors, and
+=-d1= will cause all states to be interconnected.
+
+#+BEGIN_SRC sh :results verbatim :exports code
+randaut -S3 -d0 2
+#+END_SRC
+
+#+NAME: randaut2
+#+BEGIN_SRC sh :results verbatim :exports none
+randaut -S3 -d0 2 | sed 's/\\/\\\\/'
+#+END_SRC
+
+#+RESULTS: randaut2
+#+begin_example
+digraph G {
+  0 [label="", style=invis, height=0]
+  0 -> 1
+  1 [label="0", peripheries=2]
+  1 -> 2 [label="!p0 & !p1"]
+  2 [label="2", peripheries=2]
+  2 -> 3 [label="!p0 & p1"]
+  3 [label="1", peripheries=2]
+  3 -> 2 [label="p0 & p1"]
+}
+#+end_example
+
+#+BEGIN_SRC dot :file randaut2.png :cmdline -Tpng :var txt=randaut2 :exports results
+$txt
+#+END_SRC
+#+RESULTS:
+[[file:randaut2.png]]
+
+#+BEGIN_SRC sh :results verbatim :exports code
+randaut -S3 -d1 2
+#+END_SRC
+
+#+NAME: randaut3
+#+BEGIN_SRC sh :results verbatim :exports none
+randaut -S3 -d1 2 | sed 's/\\/\\\\/'
+#+END_SRC
+
+#+RESULTS: randaut3
+#+begin_example
+digraph G {
+  0 [label="", style=invis, height=0]
+  0 -> 1
+  1 [label="0", peripheries=2]
+  1 -> 2 [label="!p0 & !p1"]
+  1 -> 1 [label="!p0 & !p1"]
+  1 -> 3 [label="p0 & p1"]
+  2 [label="2", peripheries=2]
+  2 -> 2 [label="p0 & !p1"]
+  2 -> 3 [label="p0 & !p1"]
+  2 -> 1 [label="!p0 & !p1"]
+  3 [label="1", peripheries=2]
+  3 -> 1 [label="!p0 & !p1"]
+  3 -> 3 [label="!p0 & !p1"]
+  3 -> 2 [label="p0 & p1"]
+}
+#+end_example
+
+#+BEGIN_SRC dot :file randaut3.png :cmdline -Tpng :var txt=randaut3 :exports results
+$txt
+#+END_SRC
+
+#+RESULTS:
+[[file:randaut3.png]]
+
+
+* Acceptance sets
+
+The generation of acceptance sets is controlled with the following three parameters:
+
+ - =-A= (or =--acc-sets=) controls the number of acceptance sets.
+   This can be given as a range (e.g. =-A1..3=) in case you want this
+   number to be picked at random in the range.
+ - =-a= (or =--acc-probability=) controls the probability that any
+   transition belong to a given acceptance set.
+ - =--state-acc= requests that the automaton use state-based
+   acceptance.  In this case, =-a= is the probability that a /state/
+   belong to the acceptance set.  (Because Spot only deals with
+   transition-based acceptance internally, this options force all
+   transitions leaving a state to belong to the same acceptance sets.
+   But if the output format allows state-acceptance, it will be used.)
+
+In addition, =-B= (or =--ba=) is a shorthand for =-A1 --state-acc=.
+
+
+#+BEGIN_SRC sh :results verbatim :exports code
+randaut -S3 -d0.5 -A2 -a0.2 2
+#+END_SRC
+
+#+NAME: randaut4
+#+BEGIN_SRC sh :results verbatim :exports none
+randaut -S3 -d0.5 -A2 -a0.2 2 | sed 's/\\/\\\\/'
+#+END_SRC
+
+#+RESULTS: randaut4
+#+begin_example
+digraph G {
+  0 [label="", style=invis, height=0]
+  0 -> 1
+  1 [label="0"]
+  1 -> 2 [label="!p0 & !p1\\n{1}"]
+  1 -> 3 [label="!p0 & p1"]
+  2 [label="2"]
+  2 -> 1 [label="!p0 & !p1\\n{0}"]
+  2 -> 2 [label="!p0 & !p1"]
+  3 [label="1"]
+  3 -> 2 [label="!p0 & p1\\n{1}"]
+  3 -> 3 [label="!p0 & p1"]
+}
+#+end_example
+
+#+BEGIN_SRC dot :file randaut4.png :cmdline -Tpng :var txt=randaut4 :exports results
+$txt
+#+END_SRC
+#+RESULTS:
+[[file:randaut4.png]]
+
+
+#+BEGIN_SRC sh :results verbatim :exports code
+randaut -S3 -d0.4 -B -a0.5 2
+#+END_SRC
+
+#+NAME: randaut5
+#+BEGIN_SRC sh :results verbatim :exports none
+randaut -S3 -d0.4 -B -a0.5 2 | sed 's/\\/\\\\/'
+#+END_SRC
+
+#+RESULTS: randaut5
+#+begin_example
+digraph G {
+  0 [label="", style=invis, height=0]
+  0 -> 1
+  1 [label="0", peripheries=2]
+  1 -> 2 [label="!p0 & !p1\\n{0}"]
+  1 -> 1 [label="!p0 & p1\\n{0}"]
+  2 [label="2", peripheries=2]
+  2 -> 3 [label="!p0 & p1\\n{0}"]
+  2 -> 1 [label="p0 & !p1\\n{0}"]
+  3 [label="1"]
+  3 -> 3 [label="p0 & !p1"]
+  3 -> 1 [label="p0 & !p1"]
+}
+#+end_example
+
+#+BEGIN_SRC dot :file randaut5.png :cmdline -Tpng :var txt=randaut5 :exports results
+$txt
+#+END_SRC
+#+RESULTS:
+[[file:randaut5.png]]
+
+* Determinism
+
+The output can only contain a single edge between two given states.
+By default, the label of this edge is a random assignment of all
+atomic propositions.  Two edges leaving the same state may therefore
+have the same label.
+
+If the =-D= (or =--deterministic=) option is supplied, the labels
+are generated differently: once the degree $m$ of a state has been
+decided, the algorithm will compute a set of $m$ disjoint
+Boolean formulas over the given atomic propositions, such that the
+sum of all these formulas is $\top$.  The resulting automaton is
+therefore deterministic and complete.
+
+#+BEGIN_SRC sh :results verbatim :exports code
+randaut -D -S3 -d0.6 -A2 -a0.5 2
+#+END_SRC
+
+#+NAME: randaut6
+#+BEGIN_SRC sh :results verbatim :exports none
+randaut -D -S3 -d0.6 -A2 -a0.5 2 | sed 's/\\/\\\\/'
+#+END_SRC
+
+#+RESULTS: randaut6
+#+begin_example
+digraph G {
+  0 [label="", style=invis, height=0]
+  0 -> 1
+  1 [label="0"]
+  1 -> 2 [label="p0\\n{1}"]
+  1 -> 3 [label="!p0\\n{0,1}"]
+  2 [label="1"]
+  2 -> 3 [label="!p0 & p1"]
+  2 -> 1 [label="!p0 & !p1\\n{0}"]
+  2 -> 2 [label="p0\\n{0,1}"]
+  3 [label="2"]
+  3 -> 3 [label="p0 & p1\\n{1}"]
+  3 -> 1 [label="p0 & !p1\\n{0}"]
+  3 -> 2 [label="!p0"]
+}
+#+end_example
+
+#+BEGIN_SRC dot :file randaut6.png :cmdline -Tpng :var txt=randaut6 :exports results
+$txt
+#+END_SRC
+#+RESULTS:
+[[file:randaut6.png]]
+
+
+Note that in a deterministic automaton with $a$ atomic propositions,
+it is not possible to have states with more than $2^a$ successors.  If
+the combination of =-d= and =-S= allows the situation where a state
+can have more than $2^a$ successors, the degree will be clipped to
+$2^a$.  When working with random deterministic automata over $a$
+atomic propositions, we suggest you always request more than $2^a$
+states.
+
+* Output formats
+
+The output format can be controlled using =--hoaf=, =--dot==,
+=--lbtt=, and =--spin=.  Note that =--spin= automatically implies
+=--ba=.
+
+* Generating a stream of automata
+
+Use option =-n= to specify a number of automata to build.  A negative
+value will cause an infinite number of automata to be produced.  This
+generation of multiple automata is probably useful only with =--hoaf=,
+when piped to another tool that can read this format and process
+automata in batches.
diff --git a/doc/org/tools.org b/doc/org/tools.org
index 56963c9aa..e58b03b13 100644
--- a/doc/org/tools.org
+++ b/doc/org/tools.org
@@ -36,7 +36,7 @@ corresponding commands are hidden.
 * Command-line tools
 
 - [[file:randltl.org][=randltl=]] Generate random LTL/PSL formulas.
-- [[file:ltlfilt.org][=ltlfilt=]] Filter LTL/PSL formulas.
+- [[file:ltlfilt.org][=ltlfilt=]] Filter and convert LTL/PSL formulas.
 - [[file:genltl.org][=genltl=]] Generate LTL formulas from scalable patterns.
 - [[file:ltl2tgba.org][=ltl2tgba=]] Translate LTL/PSL formulas into Büchi automata.
 - [[file:ltl2tgta.org][=ltl2tgta=]] Translate LTL/PSL formulas into Testing automata.
@@ -45,8 +45,10 @@ corresponding commands are hidden.
   Büchi automata.
 - [[file:ltlgrind.org][=ltlgrind=]] List formulas similar to but simpler than a given LTL/PSL
   formula
+- [[file:randaut.org][=randaut=]] Generate random automata.
+- [[file:autfilt.org][=autfilt=]] Filter and convert automata.
 
-* Advanced uses
+* Advanced use-cases
 
 - [[file:csv.org][Reading and writing CSV files]]
 - [[file:satmin.org][SAT-based minimization of Deterministic (Generalized) Büchi automata]]