Known numbers builds of Windows 10

6.3.9687.0
6.3.9727.0 (winmain.140410-1715)
6.3.9729.0
6.3.9740.0
6.3.9755.0
6.3.9760.0
6.3.9764.0
6.3.9776.0
6.3.9777.0
6.3.9778.0 (fbl_marketplace.140619-1430_x64fre_client_EnterpriseVL_en us-IR3_CENA_X64FREV_EN-US_ESD)
6.3.9780.0
6.3.9783.0
6.4.9786.0 (presumably the first assembly with the core NT 6.4) (winmain_prs.140629-1340_x86fre_client_Professional_en-us-IR3_CPRA_X86FRER_EN-US_ESD)
6.4.9787.0 (winmain_prs.140630-1500_x64fre_client_EnterpriseVL_en-us-IR3_CENA_X64FREV_EN-US_ESD)
6.4.9788.0 (winmain.140704-2025)
6.4.9793.0
6.4.9795 (fbl_uip_dev.140713-1834)
6.4.9803.0
6.4.9814.0 (fbl_srv2_ci_mgmt_rel.140827-2330)
6.4.9815.0
6.4.9821.0
6.4.9825.0
6.4.9829.0
6.4.9830.0
6.4.9834.0 (fbl_partner_eeap.140908-0936) (Leaked screenshots Technical Preview)
6.4.9835.0
6.4.9836.0 (140906-2314.fbl_release_CLIENTENTERPRISE_VOL_x64fre_en-us)
6.4.9841.0 (Official Version Technical Preview) (9841.fbl_release.140912-1613)
6.4.9844.0
6.4.9845.0 (140921-1448.winmain_CLIENTENTERPRISE_VOL_x64fre_en-us)
6.4.9847.0 (140923-1624.winmain_CLIENTENTERPRISE_VOL_x64fre_en-us)
6.4.9848.0 (140924-2115.fbl_bldsvc_CLIENTENTERPRISE_VOL_x64fre_en-us)
6.4.9849.0 (140926-0249.fbl_release_CLIENTENTERPRISE_VOL_x64fre_en-us) (140926-0249.fbl_release_CLIENTPRO_RET_x64fre_en-us)
6.4.9850.0
(140926-1824.winmain_CLIENTPRO_RET_x64fre_en-us) (140926-1824.winmain_CLIENTENTERPRISE_VOL_x64fre_en-us) (140926-1857.fbl_bldsvc_CLIENTENTERPRISE_VOL_x64fre_en-us) (140927-1520.fbl_release_CLIENTENTERPRISE_VOL_x64fre_en-us) (140927-1520.fbl_release_CLIENTPRO_RET_x64fre_en-us)
6.4.9851.0 (140928-1640.fbl_release_CLIENTPRO_RET_x64fre_en-us)
6.4.9852.0
(140929-1345.winmain_CLIENTPRO_RET_x64fre_en-us) (winmain_CLIENTENTERPRISE_VOL_x64fre_en-us) (140929-1714.fbl_bldsvc_CLIENTENTERPRISE_VOL_x64fre_en-us)
6.4.9853.0 (140930-1548.fbl_kpg_CLIENTENTERPRISE_VOL_x64fre_en-us)
6.4.9854.0
(141001-1402.winmain_CLIENTENTERPRISE_VOL_x64fre_en-us) (141001-1402.winmain_CLIENTPRO_RET_x64fre_en-us) (141001-1447.winmain_prs_CLIENTPRO_RET_x64fre_en-us)
6.4.9855.0
(9855.0.141002-1432.winmain_CLIENTPRO_RET_x64fre_en-us) (141002-1432.winmain_CLIENTENTERPRISE_VOL_x64fre_en-us)
6.4.9857.0
(141005-2142.fbl_release_CLIENTPRO_RET_x86fre_en-us) (141005-2029.fbl_shellinput_CLIENTENTERPRISE_VOL_x86fre_en-us) (141005-2142.fbl_release_CLIENTENTERPRISE_VOL_x86fre_en-us) (141005-1237.fbl_cdexp_CLIENTENTERPRISE_VOL_x86fre_en-us) (141005-1700.fbl_sfp_CLIENTENTERPRISE_VOL_x86fre_en-us) (141005-1324. fbl_mobs_CLIENTENTERPRISE_VOL_x86fre_en-us) (141005-1402.fbl_cde_CLIENTENTERPRISE_VOL_x86fre_en-us) (6.4.9857.0.fbl_cortana.141005-1307)
6.4.9858.0
(141006-1219.winmain_CLIENTENTERPRISE_VOL_x86fre_en-us) (141006-1219.winmain_CLIENTPRO_RET_x86fre_en-us) (141006-1819.fbl_kpg_CLIENTENTERPRISE_VOL_x86fre_en-us) (141006-2147.fbl_mobs_CLIENTENTERPRISE_VOL_x86fre_en-us) (141006-1823.fbl_cdexp_CLIENTENTERPRISE_VOL_x86fre_en-us) (141006-1823. fbl_cde_CLIENTENTERPRISE_VOL_x86fre_en-us)
6.4.9859.0
(141007-1929.fbl_lad_CLIENTENTERPRISE_VOL_x64fre_en-us) (141007-1853.fbl_mediaplat_CLIENTENTERPRISE_VOL_x64fre_en-us) (141007-1438.winmain_CLIENTENTERPRISE_VOL_x86fre_en-us) (141007-1438.winmain_CLIENTPRO_RET_x86fre_en-us)
6.4.9860.0 (Second Public Technical Prteview (9860.0.141008-2044.fbl_release_CLIENTPRO_RET)
(141008-1904.winmain_CLIENTENTERPRISE_VOL_x86fre_en-us) (141008-1904.winmain_CLIENTPRO_RET_x86fre_en-us) (141008-1934.fbl_mgmt_CLIENTENTERPRISE_VOL_x86fre_en-us) (141008-1935.fbl_mediaplat_CLIENTENTERPRISE_VOL_x64fre_en-us) (141008-1938.fbl_desk_CLIENTENTERPRISE_VOL_x64fre_en-us) (141008-2044. fbl_release_CLIENTENTERPRISE_VOL_x64fre_en-us) (141008-2044.fbl_release_CLIENTPRO_RET_x64fre_en-us) (6.4.9860.2.fbl_release_currentfr.141013-1849)
6.4.9861.0
(141009-1837.fbl_1pd_CLIENTENTERPRISE_VOL_x64fre_en-us) (141009-1837.fbl_lad_CLIENTENTERPRISE_VOL_x64fre_en-us) (141009-1807.fbl_release_CLIENTENTERPRISE_VOL_x64fre_en-us) (141009-1612.winmain_CLIENTENTERPRISE_VOL_x64fre_en-us)
6.4.9862.0 (141010-2027.fbl_desk_CLIENTENTERPRISE_VOL_x64fre_en-us)
6.4.9863.0 (fbl_mobs.141013-1802) (fbl_shellinput.141013-1401) (fbl_mgmt.141013-2227) (fbl_desk.141013-1413)
6.4.9864.0 (fbl_lad.141014-1800) (fbl_mediaplat.141014-1800) (fbl_cortana.141014-1943)
6.4.9865.0 (fbl_release.141014-1752) (fbl_desk.141015-1800) (fbl_mediaplat.141015-1945) (fbl_sfp.141015-2028)
6.4.9866.0 (fbl_mobs.141016-1831) (fbl_mgmt.141016-1740) (fbl_lad.141016-1740) (fbl_sec.141016-1938) (fbl_release.141016-1544)
Flight Level: High
6.4.9867.0 (fbl_mediaplat.141018-1703) (winmain_prs.141018-2355) (winmain.141017-1819) (fbl_release.141018-2359) (fbl_cortana.141019-0928)
Flight Level: High
6.4.9868.0 (fbl_desk.141020-1702) (fbl_mobs.141020-1604) (fbl_mgmt.141020-1857) (fbl_mediaplat.141020-1602) (fbl_1pd.141020-1629)


Windows 10 Technical Preview:
Download: http://windows.microsoft.com
Download Enterprise: http://technet.microsoft.com
Guide Windows 10 Technical Preview (English): http://www.microsoft.com