OOllddeesstt SScchheemmee IImmpplleemmeennttaattiioonnss Published April 3, 2022 _G_a_m_b_i_t _S_c_h_e_m_e[1] claims to be the third-oldest, active Scheme implementation. It seemed like an interesting case study for the _L_i_n_d_y _E_f_f_e_c_t[2], so I tracked down a few Scheme implementations for comparison. This list is sorted from oldest to youngest. A ☠ indicates implementations that had fewer than 5 commits to their repository in 2021. • _R_0_R_S[3] 1975 ☠ • _R_a_b_b_i_t[4] 1978 ☠ • _M_I_T_/_G_N_U _S_c_h_e_m_e[5] _1_9_7_9[6] • _T[7] 1982 ☠ • _C_h_e_z _S_c_h_e_m_e[8] 1985 • _O_a_k_l_i_s_p[9] 1986 ☠ • _S_c_h_e_m_e _4_8[10] 1987 ☠ • _G_a_m_b_i_t[11] 1988 • _S_I_O_D[12] 1988 ☠ • _S_C_M[13] 1990 ☠ • _G_u_i_l_e[14] 1993 • _S_T_k_l_o_s[15] _1_9_9_3[16] • _B_i_g_l_o_o[17] 1995 • _R_a_c_k_e_t[18] 1995 • _K_a_w_a[19] 1996 • _L_a_r_c_e_n_y[20] 1998 ☠ • _C_h_i_c_k_e_n[21] 2000 • _G_a_u_c_h_e[22] 2001 • _S_c_h_e_m_e _9 _f_r_o_m _E_m_p_t_y _S_p_a_c_e[23] 2007 ☠ • _Y_p_s_i_l_o_n[24] 2008 • _S_a_g_g_i_t_a_r_i_u_s[25] 2011 • _G_e_r_b_i_l[26] 2016 Scheme was _i_n_v_e_n_t_e_d[27] and R0RS published in 1975. _R_1_R_S[28] is dated 1978. Three implementations have survived from Schemeʼs first decade: MIT, Chez, and Gambit. Iʼd love to add notable, old, dead Schemes to this list. Mail me if you know of any: mm..ssccmm@@nnddrriixx..oorrgg 1: https://www.gambitscheme.org/ 2: https://en.wikipedia.org/wiki/Lindy_effect 3: http://dspace.mit.edu/bitstream/handle/1721.1/5794/AIM-349.pdf 4: https://dspace.mit.edu/handle/1721.1/6913 5: https://en.wikipedia.org/wiki/MIT/GNU_Scheme 6: https://www.reddit.com/r/scheme/comments/tve4wh/comment/i38ujqt/ 7: https://en.wikipedia.org/wiki/T_(programming_language) 8: https://en.wikipedia.org/wiki/Chez_Scheme 9: https://en.wikipedia.org/wiki/Oaklisp 10: https://en.wikipedia.org/wiki/Scheme_48 11: https://en.wikipedia.org/wiki/Gambit_(Scheme_implementation) 12: https://www.nongnu.org/muesli/ulsiod.html 13: https://en.wikipedia.org/wiki/SCM_(Scheme_implementation) 14: https://en.wikipedia.org/wiki/GNU_Guile 15: https://en.wikipedia.org/wiki/STklos 16: https://www.reddit.com/r/scheme/comments/tve4wh/comment/i39negf/ 17: https://en.wikipedia.org/wiki/Bigloo 18: https://en.wikipedia.org/wiki/Racket_(programming_language) 19: https://en.wikipedia.org/wiki/Kawa_(Scheme_implementation) 20: https://en.wikipedia.org/wiki/Larceny_(Scheme_implementation) 21: https://en.wikipedia.org/wiki/Chicken_(Scheme_implementation) 22: https://en.wikipedia.org/wiki/Gauche_(Scheme_implementation) 23: https://t3x.org/s9fes/ 24: https://en.wikipedia.org/wiki/Ypsilon_(Scheme_implementation) 25: https://bitbucket.org/ktakashi/sagittarius-scheme/src/master/ 26: https://cons.io/ 27: https://link.springer.com/article/10.1023/A:1010079421970 28: http://dspace.mit.edu/bitstream/handle/1721.1/6283/AIM-452.pdf