<s>
BitKeeper	B-Protocol
is	O
a	O
software	O
tool	O
for	O
distributed	B-Protocol
revision	I-Protocol
control	I-Protocol
of	O
computer	O
source	O
code	O
.	O
</s>
<s>
Originally	O
developed	O
as	O
proprietary	B-Application
software	I-Application
by	O
BitMover	B-Protocol
Inc.	O
,	O
a	O
privately	O
held	O
company	O
based	O
in	O
Los	O
Gatos	O
,	O
California	O
,	O
it	O
was	O
released	O
as	O
open-source	B-Application
software	I-Application
under	O
the	O
Apache-2.0	B-Application
license	O
on	O
9	O
May	O
2016	O
.	O
</s>
<s>
BitKeeper	B-Protocol
is	O
no	O
longer	O
being	O
developed	O
.	O
</s>
<s>
BitKeeper	B-Protocol
was	O
originally	O
developed	O
by	O
BitMover	B-Protocol
Inc.	O
,	O
a	O
privately	O
held	O
company	O
from	O
Los	O
Gatos	O
,	O
California	O
owned	O
by	O
Larry	O
McVoy	O
,	O
who	O
had	O
previously	O
designed	O
TeamWare	B-Protocol
.	O
</s>
<s>
BitKeeper	B-Protocol
was	O
first	O
mentioned	O
as	O
a	O
solution	O
to	O
some	O
of	O
the	O
growing	O
pains	O
that	O
Linux	B-Operating_System
was	O
having	O
in	O
September	O
1998	O
.	O
</s>
<s>
Early	O
access	O
betas	O
were	O
available	O
in	O
May	O
1999	O
and	O
on	O
May	O
4	O
,	O
2000	O
,	O
the	O
first	O
public	O
release	O
of	O
BitKeeper	B-Protocol
was	O
made	O
available	O
.	O
</s>
<s>
BitMover	B-Protocol
used	O
to	O
provide	O
access	O
to	O
the	O
system	O
for	O
certain	O
open-source	B-Application
or	O
free-software	B-Application
projects	O
,	O
one	O
of	O
which	O
was	O
the	O
source	O
code	O
of	O
the	O
Linux	B-Operating_System
kernel	I-Operating_System
.	O
</s>
<s>
The	O
license	O
for	O
the	O
"	O
community	O
"	O
version	O
of	O
BitKeeper	B-Protocol
had	O
allowed	O
for	O
developers	O
to	O
use	O
the	O
tool	O
at	O
no	O
cost	O
for	O
open	O
source	O
or	O
free	B-Application
software	I-Application
projects	O
,	O
provided	O
those	O
developers	O
did	O
not	O
participate	O
in	O
the	O
development	O
of	O
a	O
competing	O
tool	O
(	O
such	O
as	O
Concurrent	B-Application
Versions	I-Application
System	I-Application
,	O
GNU	B-Protocol
arch	I-Protocol
,	O
Subversion	B-Application
or	O
ClearCase	B-Protocol
)	O
for	O
the	O
duration	O
of	O
their	O
usage	O
of	O
BitKeeper	B-Protocol
plus	O
one	O
year	O
.	O
</s>
<s>
This	O
restriction	O
applied	O
regardless	O
of	O
whether	O
the	O
competing	O
tool	O
was	O
free	O
or	O
proprietary	B-Application
.	O
</s>
<s>
This	O
version	O
of	O
BitKeeper	B-Protocol
also	O
required	O
that	O
certain	O
meta-information	O
about	O
changes	O
be	O
stored	O
on	O
computer	O
servers	O
operated	O
by	O
BitMover	B-Protocol
,	O
an	O
addition	O
that	O
made	O
it	O
impossible	O
for	O
community	O
version	O
users	O
to	O
run	O
projects	O
of	O
which	O
BitMover	B-Protocol
was	O
unaware	O
.	O
</s>
<s>
The	O
decision	O
made	O
in	O
2002	O
to	O
use	O
BitKeeper	B-Protocol
for	O
Linux	B-Operating_System
kernel	I-Operating_System
development	O
was	O
a	O
controversial	O
one	O
.	O
</s>
<s>
Some	O
,	O
including	O
GNU	B-Application
Project	I-Application
founder	O
Richard	O
Stallman	O
,	O
expressed	O
concern	O
about	O
proprietary	B-Application
tools	O
being	O
used	O
on	O
a	O
flagship	O
free	O
project	O
.	O
</s>
<s>
While	O
project	O
leader	O
Linus	O
Torvalds	O
and	O
other	O
core	O
developers	O
adopted	O
BitKeeper	B-Protocol
,	O
several	O
key	O
developers	O
(	O
including	O
Linux	B-Operating_System
veteran	O
Alan	O
Cox	O
)	O
refused	O
to	O
do	O
so	O
,	O
citing	O
the	O
BitMover	B-Protocol
license	O
,	O
and	O
voicing	O
concern	O
that	O
the	O
project	O
was	O
ceding	O
some	O
control	O
to	O
a	O
proprietary	B-Application
developer	O
.	O
</s>
<s>
To	O
mitigate	O
these	O
concerns	O
,	O
BitMover	B-Protocol
added	O
gateways	O
which	O
allowed	O
limited	O
interoperation	O
between	O
the	O
Linux	B-Operating_System
BitKeeper	B-Protocol
servers	O
(	O
maintained	O
by	O
BitMover	B-Protocol
)	O
and	O
developers	O
using	O
CVS	B-Application
and	O
Subversion	B-Application
.	O
</s>
<s>
Even	O
after	O
this	O
addition	O
,	O
flamewars	O
occasionally	O
broke	O
out	O
on	O
the	O
Linux	B-Application
kernel	I-Application
mailing	I-Application
list	I-Application
,	O
often	O
involving	O
key	O
kernel	B-Operating_System
developers	O
and	O
BitMover	B-Protocol
's	O
CEO	O
Larry	O
McVoy	O
,	O
who	O
was	O
also	O
a	O
Linux	B-Operating_System
contributor	O
.	O
</s>
<s>
In	O
April	O
2005	O
,	O
BitMover	B-Protocol
announced	O
that	O
it	O
would	O
stop	O
providing	O
a	O
version	O
of	O
BitKeeper	B-Protocol
free	O
of	O
charge	O
to	O
the	O
community	O
,	O
giving	O
as	O
the	O
reason	O
the	O
efforts	O
of	O
Andrew	O
Tridgell	O
,	O
a	O
developer	O
employed	O
by	O
OSDL	O
on	O
an	O
unrelated	O
project	O
,	O
to	O
develop	O
a	O
client	O
which	O
would	O
show	O
the	O
metadata	O
(	O
data	O
about	O
revisions	O
,	O
possibly	O
including	O
differences	O
between	O
versions	O
)	O
instead	O
of	O
only	O
the	O
most	O
recent	O
version	O
.	O
</s>
<s>
Being	O
able	O
to	O
see	O
metadata	O
and	O
compare	O
past	O
versions	O
is	O
one	O
of	O
the	O
core	O
features	O
of	O
all	O
version-control	O
systems	O
,	O
but	O
was	O
not	O
available	O
to	O
anyone	O
without	O
a	O
commercial	O
BitKeeper	B-Protocol
license	O
,	O
significantly	O
inconveniencing	O
most	O
Linux	B-Operating_System
kernel	I-Operating_System
developers	O
.	O
</s>
<s>
Although	O
BitMover	B-Protocol
decided	O
to	O
provide	O
free	O
commercial	O
BitKeeper	B-Protocol
licenses	O
to	O
some	O
kernel	B-Operating_System
developers	O
,	O
it	O
refused	O
to	O
give	O
or	O
sell	O
licenses	O
to	O
anyone	O
employed	O
by	O
OSDL	O
,	O
including	O
Linus	O
Torvalds	O
and	O
Andrew	O
Morton	O
,	O
placing	O
OSDL	O
developers	O
in	O
the	O
same	O
position	O
as	O
other	O
kernel	B-Operating_System
developers	O
.	O
</s>
<s>
The	O
Git	B-Application
project	O
was	O
launched	O
with	O
the	O
intent	O
of	O
becoming	O
the	O
Linux	B-Operating_System
kernel	I-Operating_System
's	O
source	O
code	O
management	O
software	O
,	O
and	O
was	O
eventually	O
adopted	O
by	O
Linux	B-Operating_System
developers	O
.	O
</s>
<s>
End	O
of	O
support	O
for	O
the	O
"	O
Free	O
Use	O
"	O
version	O
of	O
BitKeeper	B-Protocol
was	O
officially	O
July	O
1	O
,	O
2005	O
,	O
and	O
users	O
were	O
required	O
to	O
switch	O
to	O
the	O
commercial	O
version	O
or	O
change	O
version	O
control	O
system	O
by	O
then	O
.	O
</s>
<s>
Commercial	O
users	O
were	O
also	O
required	O
not	O
to	O
produce	O
any	O
competing	O
tools	O
:	O
In	O
October	O
2005	O
,	O
McVoy	O
contacted	O
a	O
customer	O
using	O
commercially	O
licensed	O
BitKeeper	B-Protocol
,	O
demanding	O
that	O
an	O
employee	O
of	O
the	O
customer	O
stop	O
contributing	O
to	O
the	O
Mercurial	B-Protocol
project	O
,	O
a	O
GPL	O
source	O
management	O
tool	O
.	O
</s>
<s>
Bryan	O
O'Sullivan	O
,	O
the	O
employee	O
,	O
responded	O
,	O
"	O
To	O
avoid	O
any	O
possible	O
perception	O
of	O
conflict	O
,	O
I	O
have	O
volunteered	O
to	O
Larry	O
that	O
as	O
long	O
as	O
I	O
continue	O
to	O
use	O
the	O
commercial	O
version	O
of	O
BitKeeper	B-Protocol
,	O
I	O
will	O
not	O
contribute	O
to	O
the	O
development	O
of	O
Mercurial.	O
"	O
</s>
<s>
During	O
the	O
release	O
of	O
version	O
7.2ce	O
at	O
May	O
9	O
,	O
2016	O
,	O
BitKeeper	B-Protocol
announced	O
that	O
it	O
is	O
starting	O
to	O
move	O
from	O
proprietary	B-Application
to	O
open-source	B-Application
license	O
,	O
eventually	O
releasing	O
the	O
software	O
under	O
the	O
Apache	B-Application
License	I-Application
version	O
2	O
.	O
</s>
