<s>
XEphem	B-Application
is	O
a	O
Motif	B-Application
based	O
ephemeris	O
and	O
planetarium	O
program	O
for	O
Unix-like	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
developed	O
by	O
Elwood	O
C	B-Language
.	O
Downey	O
.	O
</s>
<s>
XEphem	B-Application
started	O
as	O
a	O
Unix	B-Application
and	O
Motif	B-Application
conversion	O
of	O
the	O
IBM	O
PC-based	O
.	O
</s>
<s>
In	O
2021	O
,	O
however	O
,	O
Downey	O
relicensed	O
XEphem	B-Application
's	O
source	O
code	O
under	O
the	B-License
MIT	I-License
License	I-License
,	O
raising	O
the	O
release	O
version	O
from	O
3.7.7	O
to	O
4.0.0	O
to	O
highlight	O
the	O
change	O
.	O
</s>
<s>
About	O
288,000	O
minor	O
planets	O
and	O
comets	B-Language
orbital	O
elements	O
from	O
the	O
IAU	O
Minor	O
Planet	O
Center	O
and	O
Lowell	O
Observatory	O
(	O
that	O
can	O
be	O
updated	O
)	O
,	O
</s>
<s>
XEphem	B-Application
is	O
a	O
client	O
for	O
Internet	O
data	O
sources	O
such	O
as	O
the	O
Digitized	O
Sky	O
Survey	O
,	O
Solar	O
and	O
Heliospheric	O
Observatory	O
,	O
AAVSO	O
light	O
curves	O
,	O
and	O
global	O
temperature	O
and	O
cloud	O
coverage	O
.	O
</s>
<s>
Through	O
the	O
Instrument	B-Application
Neutral	I-Application
Distributed	I-Application
Interface	I-Application
,	O
XEphem	B-Application
can	O
control	O
some	O
models	O
of	O
amateur	O
telescopes	O
,	O
such	O
as	O
by	O
Meade	O
,	O
Celestron	O
,	O
and	O
Vixen	O
,	O
and	O
auxiliary	O
telescope	O
components	O
.	O
</s>
<s>
While	O
the	O
free	O
version	O
of	O
XEphem	B-Application
only	O
includes	O
a	O
subset	O
of	O
the	O
SKYMAP	O
Master	O
Catalog	O
and	O
the	O
Messier	O
Catalog	O
,	O
the	O
internal	O
format	O
of	O
the	O
remaining	O
catalogs	O
can	O
be	O
inferred	O
from	O
the	O
source	O
code	O
,	O
and	O
e.g.	O
</s>
<s>
This	O
is	O
also	O
possible	O
for	O
the	O
non-stellar	O
catalogs	O
in	O
the	O
ASCII	B-Protocol
.edb	O
format	O
,	O
such	O
as	O
for	O
HYPERLEDA	O
.	O
</s>
<s>
XEphem	B-Application
can	O
also	O
read	O
several	O
astrometric	O
catalogs	O
in	O
their	O
original	O
formats	O
:	O
</s>
<s>
Numerical	O
routines	O
are	O
used	O
in	O
PyEphem	B-Application
with	O
permission	O
of	O
Elwood	O
Downey	O
.	O
</s>
