The plugin comes with various translations, which since v2.4 of the plugin can also be activated separately through the plugin´s settings:
If you want to help to translate the plugin in your language, please visit http://translate.mapsmarker.com where everyone can register and start translating immediately 
Many thanks to the translators of the following languages:
- Bengali translation thanks to Nur Hasan, http://www.answersbd.com
- Bosnian (bs_BA) thanks to Kenan Dervišević, http://dkenan.com
- Bulgarian (bg_BG) thanks to Andon Ivanov, http://coffebreak.info
- Catalan (ca) thanks to Vicent Cubells, http://vcubells.net and Efraim Bayarri, http://replicantsfactory.com
- Chinese (zh_CH) thanks to John Shen, http://www.synyan.net
- Chinese (zh_TW) thanks to jamesho Ho, http://outdooraccident.org
- Croatian (hr) thanks to Neven Pausic, http://www.airsoft-hrvatska.com and Alan Benic
- Czech (cs_CZ) thanks to Viktor Kleiner
- Danish (da_DK) thanks to Mads Dyrmann Larsen
- Dutch (nl_NL) thanks to Marijke Metz, http://www.mergenmetz.nl and Patrick Ruers http://www.stationskwartiersittard.nl
- English (en_US) by @RobertHarm
- French (fr_FR) – thanks to Vincèn Pujol, http://www.skivr.com and Rodolphe Quiedeville, http://rodolphe.quiedeville.org
- German (de_DE) by @RobertHarm
- Hindi (hi_IN) by Outshine Solutions, http://outshinesolutions.com and Guntupalli Karunakar, http://indlinux.org
- Hungarian (hu_HU) thanks to István Pintér, http://www.logicit.hu
- Indonesian (id_ID) thanks to Emir Hartato, http://whateverisaid.wordpress.com
- Italian (it_IT) thanks to Luca Barbetti
- Japanese (ja) – thanks to Shu Higashi, @higa4
- Polish translation thanks to Tomasz Rudnicki, http://www.kochambieszczady.pl and Pawel Wyszyński, http://injit.pl
- Portuguese (pt_BR) thanks to Andre Santos, http://pelaeuropa.com.br and Antonio Hammerl
- Portuguese (pt_PT) translation thanks to Joao Campos, http://www.all-about-portugal.com
- Romanian (ro_RO) translation thanks to Daniel Codrea, http://www.inadcod.com
- Russian (ru_RU) thanks to Ekaterina Golubina, supported by Teplitsa of Social Technologies – http://te-st.ru
- Slovak (sk_SK) thanks to Zdenko Podobny
- Spanish (es_ES) – thanks to David Ramírez, http://www.hiperterminal.com, Alvaro Lara, http://www.alvarolara.com and Victor Guevara, http://1sistemas.net
- Swedish (sv_SE) thanks to Olof Odier http://www.historiskastadsvandringar.se, Tedy Warsitha http://codeorig.in/ and Dan Paulsson http://www.paulsson.eu
- Ukrainian (uk_UK) thanks to Andrexj, http://all3d.com.ua
- Yiddish (yi) thanks to Raphael Finkel, http://www.cs.uky.edu/~raphael/yiddish.html
- Turkish (tr_TR) thanks to Emre Erkan, http://www.karalamalar.net
If you don´t want to use the web-based tool GlotPress at http://translate.mapsmarker.com for translations, please send me message so that I can mail you the lmm.pot file which contains all defintions and may be used by an offline editor like gettext or Poedit (Windows). If you have created your own language pack, or have an update of an existing one, you can send gettext PO and MO files to me so that I can bundle it into the next release of Leaflet Maps Marker.