Surfing Internet I found an interesting project Zmanim for Unix systems.
This tool is not that easy to use, but still reports correct information about zmanim according to Vilna Gaon rules.

Usage is the following:

$ zmanim
usage: use one of the following forms.
   zmanim #uses default location from $HOME/.zmanrc and 'today'
   zmanim  #uses default location from $HOME/.zmanrc
   zmanim   #from $HOME/.zmanrc
   zmanim    

format for $HOME/.zmanrc
[default]    

use of 'dst' means to observe daylight savings time at the appropriate dates
latitude is negative if south. longitude is negative if west

I specified Tallinn, Estonia location and it reported the following output:

$ zmanim 12/16/2009 59,26 24,44 UTC-2
======================================================
======================================================
Zmanim for 

======================================================
=== Tuesday 12/15/2009
GRA     Proportional Hour                       31 minutes
                             Candle Lighting    3:08 pm
        Shkiah               Sunset         *** 3:26 pm
8.5deg  Tzait HaChochavim    Nightfall          4:43 pm

======================================================
=== Wednesday 12/16/2009
GRA     Proportional Hour                       31 minutes
16.1deg Alot HaShachar       Daybreak           6:49 am
11 deg  Mesheyakir           Earliest Talit     7:32 am
        Netz                 Sunrise        *** 9:12 am
GRA     Sof Zman Sh'ma       Latest Sh'ma       10:46 am
GRA     Sof Zman T'fila      Latest T'fila      11:17 am
        Chatzot              Midday             12:19 pm
GRA     Mincha Gedola                           12:34 pm
GRA     Mincha Katanah                          2:08 pm
GRA     Plag Hamincha                           2:47 pm
                             Candle Lighting    3:08 pm
        Shkiah               Sunset         *** 3:26 pm
8.5deg  Tzait HaChochavim    Nightfall          4:44 pm

.zmanrc file is not used by zmanim. At least on my system Ubuntu 9.10.
I added the following string to .zmanrc
[default] Tallinn,Estonia 59,26 24,44 UTC-2
Then executed zmanim binary file and it returned just usage, which means that it doesn’t use .zmanrc settings.

Installation package for Ubuntu can be obtained from here.

Popularity: 15% [?]

command line, linux, ubuntu, zmanim